All Tests

 Dysthymia, sometimes referred to as mild, chronic depression, is less severe and has fewer symptoms than major depression. With dysthymia, the depression symptoms can linger for a long period of time, often two years or longer. Those who suffer from dysthymia can also experience periods of major depression--sometimes called "double depression." In modern diagnostic classification systems, dysthymia and chronic depression are now both referred to as 'persistent depressive disorders.
 

A drug test looks for the presence of one or more illegal or prescription drugs in your urine, blood, saliva, hair, or sweat. Urine testing is the most common type of drug screening. The drugs most often tested for include:

• Marijuana
• Opioids, such as heroin, codeine, oxycodone, morphine, hydrocodone, and fentanyl
• Amphetamines, including methamphetamine
• Cocaine
• Steroids
• Barbiturates, such as phenobarbital and secobarbital
• Phencyclidine (PCP)

Other names: drug screen, drug test, drugs of abuse testing, substance abuse testing, toxicology screen, tox screen, sports doping tests.

Even some of the most stunning women often have to resort to concealers and make-up to hide their dark circles. Not only do these under-eye circles make you look much older than what you actually are, but they also have you looking ill or unhealthy.

Before we even begin this natural journey, let me tell you that dark circles take time to cure and require great discipline. A regular skin and health care program should be followed, by the book, so do not expect magic to happen overnight.

Even some of the most stunning women often have to resort to concealers and make-up to hide their dark circles. Not only do these under-eye circles make you look much older than what you actually are, but they also have you looking ill or unhealthy.Before we even begin this natural journey, let me tell you that dark circles take time to cure and require great discipline. A regular skin and health care program should be followed, by the book, so do not expect magic to happen overnight.

Diaper rash: An inflammatory reaction localized to the area of skin usually covered by the diaper. It can have many causes, including infections (yeast, bacterial, or viral), friction irritation, chemical allergies (perfumes, soaps), sweat, decomposed urine, and plugged sweat glands. Most diaper rash problems can be solved by cleansing the skin with nonperfumed, gentle products; changing diapers frequently; and exposing the affected skin area to air. Commercially available diaper rash ointments may be helpful for prevention but may actually cause further irritation if used on the inflamed areas. Also called diaper dermatitis.

Skin pigmentation disorders are conditions that cause the skin to appear lighter or darker than normal, or blotchy and discolored.

A fold of fat that some people have under their chin and that looks like a second chin

Dizziness: Painless head discomfort with many possible causes including disturbances of vision, the brain, balance (vestibular) system of the inner ear, and gastrointestinal system. Dizziness is a medically indistinct term which laypersons use to describe a variety of conditions ranging from lightheadedness, unsteadiness to vertigo.

Dry hair develops when your hair doesn't get or retain enough moisture. This reduces its sheen and can make it appear frizzy, lifeless, and dull. ... If your hair is healthy, natural oils in the outer layer help protect the inner layers. They also reflect light, making your hair appear shiny.

Dry mouth: The condition of not having enough saliva to keep the mouth wet. This is due to inadequate function of the salivary glands. Everyone has dry mouth once in a while when they are nervous, upset or under stress. But if someone has a dry mouth most all of the time, it can be uncomfortable and lead to serious health problems.
Dry mouth can cause difficulties in tasting, chewing, swallowing, and speaking. If it goes untreated, severe dry mouth can also lead to increased levels of tooth decay and infections of the mouth such as thrush. Severe dry mouth is not a normal part of aging. It can be a clue to systemic diseases such as Sjogren syndrome, systemic lupus erythematosus, rheumatoid arthritis, scleroderma, sarcoidosis, amyloidosis, and hypothyroidism. Some medications can also cause dry mouth.

Dry skin: Abnormally dry skin. Can be caused by a dry climate, winter weather, severe deficiency of vitamin A, systemic illness, overexposure to sunlight, or medication. The skin loses moisture. It may crack and peel. Or it may become irritated, inflamed, and itch. Bathing frequently, especially with soaps, can contribute to dry skin.
With dry skin, it can help to keep baths or showers short in warm water with as little soap as possible, drying the skin gently -- pat without rubbing. Dry skin can also usually be addressed by the use of over-the-counter (OTC) topical preparations for dry skin. If these products do not relieve the condition, see a dermatologist for more specific remedies.

More than half of all girls and women suffer from dysmenorrhea (cramps), a dull or throbbing pain that usually centers in the lower mid-abdomen, radiating toward the lower back or thighs. Menstruating women of any age can experience cramps.
While the pain may be only mild for some women, others experience severe discomfort that can significantly interfere with everyday activities for several days each month.

Have you ever noticed how the skin on your elbows and knees is often darker than the rest of the skin on your arms and legs? It's a bit funny-looking, isn't it? Some people think it's the result of dirt (and sometimes it is), but you'd be surprised to find that dirt often has nothing to do with the dark spots on your elbows and knees.

To lighten your dark lips, it is essential to know first what causes dark lips. If you can identify the reasons for your dark lips, you can easily treat your lips.

Black neck is a term used to describe a condition in which the skin on your neck is noticeably darker than the surrounding skin, also referred to as “dark neck.” The change in color may be alarming and make you self-conscience, however, in most cases it isn’t cause for concern nor is it contagious.

In some cases, however, this skin darkening may be a warning sign of something more serious, so it’s important to see a doctor to determine the cause and begin any necessary treatment. Read on to learn more about black neck, what causes it, and how to treat it

Dark underarms can be defined as the dark coloration of skin in the underarm region compared to the rest of the body. It is a problem many individuals find embarrassing. Ascertaining the reason can help to alleviate the problem effectively. 

Excessive loss of body water. Diseases of the gastrointestinal tract that cause vomiting or diarrhea may lead to dehydration. There are a number of other causes of dehydration including heat exposure, prolonged vigorous exercise, kidney disease, and medications that cause voiding (diuretics).

One clue to dehydration is a rapid drop in weight. A loss of over 10% (15 pounds in a person weighing 150 pounds) is considered severe.

Inflammation of the skin, either due to an inherent skin defect, direct contact with an irritating substance, or to an allergic reaction. Symptoms of dermatitis include redness, itching, and in some cases blistering.

Eczema can be particularly severe and difficult to treat once it is established. Treatment is two-fold. People who suffer from dermatitis must identify and avoid substances that cause attacks. During attacks they may use topical treatments, such as steroid creams.

Detoxification is one of the more widely used treatments and concepts in alternative medicine. It is based on the principle that illnesses can be caused by the accumulation of toxic substances (toxins) in the body. Eliminating existing toxins and avoiding new toxins are essential parts of the healing process. Detoxification utilizes a variety of tests and techniques.

Type 2 diabetes, once known as adult-onset or noninsulin-dependent diabetes, is a chronic condition that affects the way your body metabolizes sugar (glucose), your body's important source of fuel.

With type 2 diabetes, your body either resists the effects of insulin — a hormone that regulates the movement of sugar into your cells — or doesn't produce enough insulin to maintain a normal glucose level.

More common in adults, type 2 diabetes increasingly affects children as childhood obesity increases. There's no cure for type 2 diabetes, but you may be able to manage the condition by eating well, exercising and maintaining a healthy weight. If diet and exercise aren't enough to manage your blood sugar well, you also may need diabetes medications or insulin therapy.

Does your hair feel brittle and stiff? Dyeing, bleaching, straightening or blowing out your hair a lot can damage it over time. These processes dry out your hair and leave it prone to breakage and split ends. Once your hair is damaged, the best way to restore it is to give it time to grow back in healthy and strong. Use deep conditioning treatments to help bring back its luster, and be healthy from the inside out to promote the growth of new healthy hair.

Dandruff is a skin condition that affects mainly the scalp. Symptoms include flaking and sometimes mild itchiness.It can result in social or self-esteem problems. A more severe form of the condition, which includes inflammation of the skin, is known as seborrheic dermatitis.

The cause is unclear but believed to involve a number of genetic and environmental factors. The condition may worsen in the winter.It is not due to poor hygiene. The underlying mechanism involves the over growth of skin cells.Diagnosis is based on symptoms.

There is no known cure.The typical treatment is with antifungal cream such as ketoconazole. Dandruff affects about half of adults. Onset is usually at puberty. Males are more often affected than females.Rates decrease after the age of 50.

Child development entails the biological, psychological and emotional changes that occur in human beings between birth and the end of adolescence, as the individual progresses from dependency to increasing autonomy. It is a continuous process with a predictable sequence, yet having a unique course for every child. It does not progress at the same rate and each stage is affected by the preceding developmental experiences. Because these developmental changes may be strongly influenced by genetic factors and events during prenatal life, genetics and prenatal development are usually included as part of the study of child development. Related terms include developmental psychology, referring to development throughout the lifespan, and pediatrics, the branch of medicine relating to the care of children. Developmental change may occur as a result of genetically-controlled processes known as maturation,[1] or as a result of environmental factors and learning, but most commonly involves an interaction between the two. It may also occur as a result of human nature and our ability to learn from our environment.

There are various definitions of periods in a child's development, since each period is a continuum with individual differences regarding start and ending. Some age-related development periods and examples of defined intervals are: newborn (ages 0–4 weeks); infant (ages 4 weeks – 1 year); toddler (ages 1–3 years); preschooler (ages 4–6 years); school-aged child (ages 6–12 years); adolescent (ages 13–18).[2]

Promoting child development through parental training, among other factors, promotes excellent rates of child development.[3] Parents play a large role in a child's life, socialization, and development. Having multiple parents can add stability to the child's life and therefore encourage healthy development.[4] Another influential factor in a child's development is the quality of their care. Child care programs present a critical opportunity for the promotion of child development.

The optimal development of children is considered vital to society and so it is important to understand the social, cognitive, emotional, and educational development of children. Increased research and interest in this field has resulted in new theories and strategies, with specific regard to practice that promotes development within the school system. There are also some theories that seek to describe a sequence of states that compose child developmen

The best way to understand the way that skin discoloration occurs is to understand how the skin gets and maintains its color. The epidermis, the outer layer of your skin, contains a bunch of cells called melanocytes. These cells have many functions, but one of their main jobs is to protect the skin. When it comes to protecting the skin from the sun, the melanocytes do so by darkening it with a pigment called melanin.

Melanin is responsible for making the skin look darker when you are exposed to the sun, but the body, for some reason, will either stop producing melanin in specific areas of the skin, or put its production into overdrive. Sometimes the skin discoloration can affect the entire body, a specific part of the body, or it can occur in just a few random places on the skin

Drug rehabilitation (often drug rehab or just rehab) is the processes of medical or psychotherapeutic  treatment for dependency on psychoactive substances such as alcohol, prescription drugs, and street drugs such as cocaine, heroin or amphetamines. The general intent is to enable the patient to confront substance dependence, if present, and cease substance abuse to avoid the psychological, legal, financial, social, and physical consequences that can be caused, especially by extreme abuse. Treatment includes medication for depression or other disorders, counseling by experts and sharing of experience with other addicts.

The colon is a long tube-like structure approximately 6 feet in length that stores and then eliminates waste material left over after digestion of food in the small intestine takes place. It is thought that pressure within the colon causes bulging pockets of tissue (sacs) that push out from the colonic walls as a person ages. A small bulging sac pushing outward from the colon wall is called a diverticulum. More than one bulging sac is referred to in the plural as diverticula. Diverticula can occur throughout the colon but are most common near the end of the left colon, referred to as the sigmoid colon, in Western countries. In Asia, the diverticula occur mostly on the right side of the colon. The condition of having these diverticula in the colon is called diverticulosis.

Diverticula are common in the Western world but are rare in areas such as Asia and Africa. Diverticula increase with age. They are uncommon before the age of 40, but are seen in more than 74% of people over the age of 80 years in the U.S. A person with diverticulosis usually has few or no symptoms. The most common symptoms associated with diverticulosis are abdominal pain, constipation, and diarrhea. In some of these patients the symptoms may be due to the concomitant presence of irritable bowel syndrome (IBS) or abnormalities in the function of the muscles of the sigmoid colon (in which case it is referred to as diverticular disease); simple diverticula should cause no symptoms. Occasionally, bleeding originates from a diverticulum, and it is referred to as diverticular bleeding.

Down syndrome is a set of physical and mental traits caused by a gene problem that happens before birth. Children who have Down syndrome tend to have certain features, such as a flat face and a short neck. They also have some degree of intellectual disability. This varies from person to person. But in most cases it is mild to moderate.

Down syndrome is a lifelong condition. But with care and support, children who have Down syndrome can grow up to have healthy, happy, productive lives.

Drug addiction is a chronic, often relapsing brain disease that causes compulsive drug seeking and use, despite harmful consequences to the drug addict and those around them. Drug addiction is a brain disease because the abuse of drugs leads to changes in the structure and function of the brain. Although it is true that for most people the initial decision to take drugs is voluntary, over time the changes in the brain caused by repeated drug abuse can impair a person's self-control and ability to make sound decisions, and at the same time create an intense impulse to take drugs.

It is because of these changes in the brain that it is so challenging for a person to stop abusing drugs. Fortunately, there are treatments that help people to counteract addiction's powerful disruptive effects and regain control of their lives. Research shows that combining addiction treatment medications, when appropriate, with behavioral therapy is the best way to ensure success for most patients. Treatment approaches that are tailored to each patient's drug abuse patterns and any concurrent medical, psychiatric, and social problems can help achieve  sustained recovery and a life without drugs.

As with other chronic diseases, such as diabetes, asthma, or heart disease, drug addiction can be managed effectively. Yet, it is not uncommon for a person to relapse and begin abusing drugs again. Relapse does not signal failure; rather, it indicates that treatment should be reinstated or adjusted, or that alternate treatment is needed to help the person regain control and recover.

Preventive dentistry is the modern way of helping you keep a healthy mouth. It helps you to keep your teeth, and means you need to have less dental treatment. The two main causes of tooth loss are decay and gum disease. The better you prevent or deal with these two problems, the more chance you will have of keeping your teeth for life.

When the dental team and patient work together, this can help to prevent the need for treatment - especially fillings and extractions. Your dental team may recommend a course of treatment to get your mouth into good condition, and then work out a ‘maintenance plan' to help you keep it that way.

The key to keeping a bright, healthy smile throughout adulthood is to practice proper oral hygiene. Adults can get cavities, as well as gum disease that can lead to serious problems. Throughout your adult life, it's important to continue to:

Brush twice a day with fluoride toothpaste to remove dental plaque – the sticky film on your teeth that's the main cause of tooth decay and inflammation of the gums, called gingivitis.

Floss daily to remove plaque from between your teeth and under your gum line, before it can harden into tartar. Once tartar has formed, it can only be removed by a dental hygienist during a professional cleaning.

Limit sugary or starchy foods, especially sticky snacks. The more often you snack between meals, the more chances you give bacteria to create the acids that attack your tooth enamel.Visit your dentist regularly for professional cleanings and checkups.

Does the word "diet" immediately make you think of an unpleasant weight-loss regimen?If it did, you are probably not alone. For example, consider the use of the term "diet" in marketing food products—it usually describes foods low in calories, such as diet soda.But there is another meaning of this word. Diet can also refer to the food and drink a person consumes daily and the mental and physical circumstances connected to eating. Nutrition involves more than simply eating a “good” diet—it is about nourishment on every level. It involves relationships with family, friends, nature (the environment), our bodies, our community, and the world.

Dengue fever is a disease caused by a family of viruses transmitted by mosquitoes. It is an acute illness of sudden onset that usually follows a benign course with symptoms such as headache, fever, exhaustion, severe muscle and joint pain, swollen lymph nodes (lymphadenopathy), and rash. The presence of fever, itchy rash, and headache (the "dengue triad") is characteristic of dengue. Other signs of dengue fever include bleeding gums, severe pain behind the eyes, and red palms and soles.

Dengue (pronounced DENG-gay) can affect anyone but tends to be more severe in people with compromised immune systems. Because it is caused by one of five serotypes of the dengue virus, it is possible to get dengue fever multiple times. However, an attack of dengue produces immunity for a lifetime to that particular viral serotype to which the patient was exposed.

Dengue goes by other names, including "breakbone fever" or "dandy fever." Victims of dengue often have contortions due to the intense pain in the joints, muscles, and bones, hence the name breakbone fever. Slaves in the West Indies who contracted dengue were said to have dandy fever because of their postures and gait.

Degenerative disc disease is not really a disease but a term used to describe the normal changes in your spinal discs camera.gif as you age. Spinal discs are soft, compressible discs that separate the interlocking bones (vertebrae) that make up the spine. The discs act as shock absorbers for the spine, allowing it to flex, bend, and twist. Degenerative disc disease can take place throughout the spine, but it most often occurs in the discs in the lower back (lumbar region) and the neck (cervical region).

Dementia isn't a specific disease. Instead, dementia describes a group of symptoms affecting memory, thinking and social abilities severely enough to interfere with daily functioning.

Though dementia generally involves memory loss, memory loss has different causes. So memory loss alone doesn't mean you have dementia.

Alzheimer's disease is the most common cause of a progressive dementia in older adults, but there are a number of causes of dementia. Depending on the cause, some dementia symptoms can be reversed.

Diabetes insipidus (die-uh-BEE-teze in-SIP-uh-dus) is an uncommon disorder that causes an imbalance of water in the body. This imbalance leads to intense thirst even after drinking fluids (polydipsia), and excretion of large amounts of urine (polyuria).

While the names diabetes insipidus and diabetes mellitus sound similar, they're not related. Diabetes mellitus — which can occur as type 1 or type 2 — is the more common form of diabetes.

There's no cure for diabetes insipidus, but treatments are available to relieve your thirst and normalize your urine output.

Diabetes mellitus (or diabetes) is a chronic, lifelong condition that affects your body's ability to use the energy found in food. There are three major types of diabetes: type 1 diabetes, type 2 diabetes, and gestational diabetes.

All types of diabetes mellitus have something in common. Normally, your body breaks down the sugars and carbohydrates you eat into a special sugar called glucose. Glucose fuels the cells in your body. But the cells need insulin, a hormone, in your bloodstream in order to take in the glucose and use it for energy. With diabetes mellitus, either your body doesn't make enough insulin, it can't use the insulin it does produce, or a combination of both.

Since the cells can't take in the glucose, it builds up in your blood. High levels of blood glucose can damage the tiny blood vessels in your kidneys, heart, eyes, or nervous system. That's why diabetes -- especially if left untreated -- can eventually cause heart disease, stroke, kidney disease, blindness, and nerve damage to nerves in the feet.

A dislocation is an injury to a joint — a place where two or more bones come together — in which the ends of your bones are forced from their normal positions. This painful injury temporarily deforms and immobilizes your joint.

Dislocation is most common in shoulders and fingers. Other sites include elbows, knees and hips. If you suspect a dislocation, seek prompt medical attention to return your bones to their proper positions.

When treated properly, most dislocations return to normal function after several weeks of rest and rehabilitation. However, some joints, such as your shoulder, may have an increased risk of repeat dislocation.

Dissociative disorders are mental disorders that involve experiencing a disconnection and lack of continuity between thoughts, memories, surroundings, actions and identity. People with dissociative disorders escape reality in ways that are involuntary and unhealthy and cause problems with functioning in everyday life.

Dissociative disorders usually develop as a reaction to trauma and help keep difficult memories at bay. Symptoms — ranging from amnesia to alternate identities — depend in part on the type of dissociative disorder you have. Times of stress can temporarily worsen symptoms, making them more obvious.

Treatment for dissociative disorders may include talk therapy (psychotherapy) and medication. Although treating dissociative disorders can be difficult, many people learn new ways of coping and lead healthy, productive lives.

A double uterus is a rare congenital abnormality. In a female fetus, the uterus starts out as two small tubes. As the fetus develops, the tubes normally join to create one larger, hollow organ — the uterus.

Sometimes, however, the tubes don't join completely. Instead, each one develops into a separate structure. A double uterus may have one opening (cervix) into one vagina, or each uterine cavity may have a cervix. In many cases, a thin wall of tissue runs down the length of the vagina, dividing it into two separate openings.

Women who have a double uterus often have successful pregnancies. But the condition can increase the risk of miscarriage or premature birth.

A drug allergy is the abnormal reaction of your immune system to a medication. Any medication — over-the-counter, prescription or herbal — is capable of inducing a drug allergy. However, a drug allergy is more likely with certain medications.

The most common signs and symptoms of drug allergy are hives, rash or fever. A drug allergy may cause serious reactions, including a life-threatening condition that affects multiple body systems (anaphylaxis).

A drug allergy is not the same as a drug side effect, a known possible reaction listed on a drug label. A drug allergy is also different from drug toxicity caused by an overdose of medication.

Dry eyes is a common condition that occurs when your tears aren't able to provide adequate lubrication for your eyes. Tears can be inadequate for many reasons. For example, dry eyes may occur if you don't produce enough tears or if you produce poor-quality tears.

Dry eyes feel uncomfortable. If you have dry eyes, your eyes may sting or burn. You may experience dry eyes in certain situations, such as on an airplane, in an air-conditioned room, while riding a bike or after looking at a computer screen for a few hours.

Treatments for dry eyes may make you more comfortable. These treatments can include lifestyle changes and eyedrops. You'll likely need to take these measures indefinitely to control the symptoms of dry eyes.

The typical scenario for dry socket is the occurrence of throbbing pain about two to four days after the tooth is extracted. Dry socket pain is often accompanied by bad breath and a foul taste in the mouth. With this onset of pain, it is obvious that proper healing has been interrupted.

Dry socket is a condition in which there is inflammation of the jawbone (or alveolar bone) after a tooth extraction. It is also referred to as "alveolar osteitis" and is one of the many complications that can occur from a tooth extraction. The occurrence of dry socket is relatively rare, occurring in about 2% of tooth extractions. However, that percentage rises to at least 20% when it involves the removal of mandibular impacted third molars (lower wisdom teeth).

Dumping syndrome is a condition that can develop after surgery to remove all or part of your stomach or after surgery to bypass your stomach to help you lose weight. Also called rapid gastric emptying, dumping syndrome occurs when food, especially sugar, moves from your stomach into your small bowel too quickly.

Most people with dumping syndrome develop signs and symptoms, such as abdominal cramps and diarrhea, 10 to 30 minutes after eating. Other people have symptoms one to three hours after eating, and still others have both early and late symptoms.

Generally, you can help prevent dumping syndrome by changing your diet after surgery. Changes might include eating smaller meals and limiting high-sugar foods. In more-serious cases of dumping syndrome, you may need medications or surgery.

Dust mite allergy is an allergic reaction to tiny bugs that commonly live in house dust. Signs of dust mite allergy include those common to hay fever, such as sneezing and runny nose. Many people with dust mite allergy also experience signs of asthma, such as wheezing and difficulty breathing.

Dust mites, close relatives of ticks and spiders, are too small to see without a microscope. Dust mites eat skin cells shed by people, and they thrive in warm, humid environments. In most homes, such items as bedding, upholstered furniture and carpeting provide an ideal environment for dust mites.

By taking steps to reduce the number of dust mites in your home, you may get control of dust mite allergy. Medications or other treatments are sometimes necessary to relieve symptoms and manage asthma.

Dwarfism is a condition of short stature. It is defined by the advocacy group Little People of America (LPA) as an adult height of 4 feet 10 inches or under, as a result of a medical or genetic condition. Although other groups may extend the criteria for certain forms of dwarfism to 5 feet, the average height of an adult with dwarfism is 4 feet.

There are two main categories of dwarfism -- disproportionate and proportionate. Disproportionate dwarfism is characterized by an average-size torso and shorter arms and legs or a shortened trunk with longer limbs. In proportionate dwarfism, the body parts are in proportion but shortened.

Dysarthria is a condition in which the muscles you use for speech are weak or you have difficulty controlling them. Dysarthria often is characterized by slurred or slow speech that can be difficult to understand.

Common causes of dysarthria include nervous system (neurological) disorders such as stroke, brain injury, brain tumors, and conditions that cause facial paralysis or tongue or throat muscle weakness. Certain medications also can cause dysarthria.

Dysarthria treatment is directed at treating the underlying cause of your condition when possible, which may improve your speech. You may have speech therapy to help improve speech. For dysarthria caused by prescription medications, changing or discontinuing the medications may help.

Dyshidrosis, also known as dyshidrotic eczema or pompholyx, is a skin condition in which very small, fluid-filled blisters appear on the palms of your hands and the sides of your fingers. The soles of your feet also can be affected.

The blisters that occur in dyshidrosis generally last around three weeks and cause intense itching. Once the blisters of dyshidrosis dry, your skin may appear scaly. The blisters typically recur, sometimes before your skin heals completely from the previous blisters.

Treatment for dyshidrosis most often includes creams or ointments that you rub on the affected skin. In severe cases, your doctor may suggest corticosteroid pills, such as prednisone, or injections.

Indigestion (dyspepsia) is a functional disease in which the gastrointestinal (GI) organs, primarily the stomach and first part of the small intestine (and occasionally the esophagus), function abnormally. It is a chronic disease in which the symptoms fluctuate in frequency and intensity usually over many months or years. It may occur every day or intermittently for days or weeks at a time followed by days or weeks of relief (a pattern referred to as periodicity).

Difficulty swallowing (dysphagia) means it takes more time and effort to move food or liquid from your mouth to your stomach. Dysphagia may also be associated with pain. In some cases, swallowing may be impossible.

Occasional difficulty swallowing, which may occur when you eat too fast or don't chew your food well enough, usually isn't cause for concern. But persistent dysphagia may indicate a serious medical condition requiring treatment.

Dysphagia can occur at any age, but it's more common in older adults. The causes of swallowing problems vary, and treatment depends on the cause.

Dehydroepiandrosterone (DHEA) is the principal human C-19 steroid. DHEA has very low androgenic potency, but serves as the major direct or indirect precursor for most sex steroids. DHEA is secreted by the adrenal gland and production is at least partly controlled by adrenocorticotropic hormone (ACTH). The bulk of DHEA is secreted as a 3-sulfoconjugate dehydroepiandrosterone sulfate (DHEAS). Both hormones are albumin bound, but DHEAS binding is much tighter. As a result, circulating concentrations of DHEAS are much higher (>100-fold) compared to DHEA. In most clinical situations, DHEA and DHEAS results can be used interchangeably. In gonads and several other tissues, most notably skin, steroid sulfatases can convert DHEAS back to DHEA, which can then be metabolized to stronger androgens and to estrogens.

During pregnancy, DHEA/DHEAS and their 16-hydroxylated metabolites are secreted by the fetal adrenal gland in large quantities. They serve as precursors for placental production of the dominant pregnancy estrogen, estriol. Within weeks after birth, DHEA/DHEAS levels fall by 80% or more and remain low until the onset of adrenarche at age 7 or 8 in girls and age 8 or 9 in boys. Adrenarche is a poorly understood phenomenon, peculiar to higher primates, that is characterized by a gradual rise in adrenal androgen production. It precedes puberty, but is not casually linked to it. Early adrenarche is not associated with early puberty or with any reduction in final height or overt androgenization. However, girls with early adrenarche may be at increased risk of polycystic ovarian syndrome as adults and some boys may develop early penile enlargement.

Following adrenarche, DHEA/DHEAS levels increase until the age of 20 to a maximum roughly comparable to that observed at birth. Levels then decline over the next 40 to 60 years to around 20% of peak levels. The clinical significance of this age-related drop is unknown and trials of DHEA/DHEAS replacement in the elderly have not produced convincing benefits. However, in young and old patients with primary adrenal failure, the addition of DHEA/DHEAS to corticosteroid replacement has been shown in some studies to improve mood, energy, and sex drive.

Dehydroepiandrosterone sulfate (DHEAS) is a male sex hormone (androgen) that is present in both men and women. This test measures the level of DHEAS in the blood.

DHEAS:

Plays a role in developing male secondary sexual characteristics at puberty

Can be converted by the body into more potent androgens, such as testosterone and androstenedione

Can be converted into the female hormone estrogen

DHEAS is produced almost exclusively by the adrenal glands, with smaller amounts being produced by a woman's ovaries and a man's testicles.

It is useful as a marker for adrenal gland function. Adrenal tumors (cancerous and non-cancerous) and adrenal hyperplasia can lead to the overproduction of DHEAS. Rarely, an ovarian tumor may produce DHEAS.

Dengue fever is a viral infection transmitted to humans by mosquitoes that live in tropical and subtropical climates and carry the virus. Blood testing detects the dengue virus or antibodies produced in response to dengue infection.

According to the Centers for Disease Control and Prevention (CDC), dengue infections have been reported in more than 100 countries from parts of Africa, the Americas, the Caribbean, the Eastern Mediterranean, Southeast Asia, and the Western Pacific. It is a fast emerging infectious disease, according to the World Health Organization (WHO), with an increasing number of cases and countries affected throughout the world. The actual number is not known because about 75% of cases are asymptomatic, but a recent estimate put the number of annual dengue infections as high as 390 million. Approximately 50 to 100 million symptomatic cases occur annually worldwide.

In the U.S., the majority of dengue cases occur in travelers returning from areas where dengue is endemic. Most dengue cases in U.S. citizens occur in people who live in Puerto Rico, the U.S. Virgin Islands, Samoa and Guam. Outbreaks where a large number of cases occur in a defined area are rare in the U.S. In recent years, there have been small outbreaks in Texas and Hawaii and a few cases diagnosed in southern Florida.

The overnight dexamethasone suppression test checks to see how taking a steroid medicine called dexamethasone changes the levels of the hormone cortisol in the blood. This test checks for a condition in which large amounts of cortisol are produced by the adrenal glands (Cushing's syndrome).

Normally, when the pituitary gland camera.gif makes less adrenocorticotropic hormone (ACTH), the adrenal glands camera.gif make less cortisol. Dexamethasone, which is like cortisol, lowers the amount of ACTH released by the pituitary gland. This in turn lowers the amount of cortisol released by the adrenal glands.

After a dose of dexamethasone, cortisol levels often stay very high in people who have Cushing's syndrome. Sometimes other conditions can keep cortisol levels high during this test. Examples include major depression, alcoholism, stress, obesity, kidney failure, pregnancy, and uncontrolled diabetes.

The night before the blood test, you will take a dexamethasone pill. The next morning, the cortisol level in your blood will be measured. If your cortisol level stays high, Cushing's syndrome may be the cause.

An ACTH test is sometimes done at the same time as the cortisol test.

A dexamethasone suppression test is primarily used to help diagnose Cushing syndrome. Cushing syndrome indicates that you have an abnormally high level of cortisol. Cortisol is a steroid hormone produced by the body during high levels of stress. (Abnormally low cortisol levels can be a sign of Addison’s disease, which is not diagnosed by this test.)

X-ray imaging, also called radiography, is a fast and easy way to identify and diagnose bone injuries and disorders such as arthritis, cancer, osteoporosis, fractures and infections. It is also used in conjunction with orthopedic surgery to ensure that a fracture or other injury has been properly aligned, and it can aid in the detection and diagnosis of abnormalities in the chest organs, including the heart and lungs. X-rays may be followed up with MRI, PET, CT, or ultrasound imaging if further testing is needed.

Dihydrotestosterone (DHT) is a potent form of testosterone required for male sexual development. However, aging men tend to have higher levels of DHT that could lead to problems such as hair loss and prostate dysfunction.

Additionally, men and women on testosterone therapy should always check their testosterone blood level to make sure that it stays within an optimal range. Remember, women with higher levels of DHT can also lose their hair.

A DLC blood test is one which measures the percentage of every single type of WBCs in the body. There are five types of normal WBCs in the blood. Their respective normal range in adults is as follows:

Neutrophils or Polymorphs: 40 - 60%

Lymphocytes (B and T cells): 20 - 40%

Monocytes: 2 - 8%

Eosinophils: 1 - 4%

Basophils: 0.5 - 1%

Band or young neutrophils: 0 - 3%

Speaking on the relevance of TLC and DLC blood tests, our expert Dr Gita Prakash, says, "These are one of the most common blood tests that we do. It tells us if there is any fever, urine infection, cough, etc." 

She goes on to add, "TLC and DLC blood tests are tests done at a primary level for a patient, because they give you a basic idea about the kind of disease you are suffering from. It also gives you an idea if there is anything more serious. I would say that TLC and DLC are good tests to get done if you are suffering from any kind of problem." 

So, how often should one get a TLC and DLC test done? "Anyone who comes to me with a problem, TLC and DLC are the basic tests that I suggest them to get done. In the report, if TLC is high, it means that there is some kind of infection. If the TLC is lower than normal, it could be a typhoid, dengue, viral fever, etc. The same goes with DLC. So these tests tell you everything about the kind of illness you are looking at," says Dr. Gita while further mentioning that by correlating the symptoms with the test results, one can diagnose the particular disease  that a patient is suffering from.

Drugs of abuse testing is the detection of one or more illegal and/or prescribed substances in the urine, blood, saliva, hair, or sweat. Testing detects substances not normally found in the body, with the exception of some hormones and steroids measured as part of sports testing.

Drug abuse testing usually involves an initial screening test followed by a second test that identifies and/or confirms the presence of a drug or drugs. Most laboratories use commercially available tests that have been developed and optimized to screen urine for the "major drugs of abuse."

For most drugs of abuse testing, laboratories compare results of initial screening with a predetermined cut-off. Anything below that cut-off is considered negative; anything above is considered a positive screening result. In addition, labs might perform testing for masking agents (adulterants). These may either interfere with testing or dilute a urine sample.

Among drugs of abuse, each class of drug may contain a variety of chemically similar substances. Legal substances that are chemically similar to illegal ones can produce a positive screening result. Positive screening tests are considered presumptive. Therefore, screening tests that are positive for one or more classes of drugs are frequently confirmed with a secondary test that identifies the exact substance present using a very sensitive and specific method, such as gas chromatography/mass spectrometry (GC/MS) or liquid chromatography-tandem mass spectrometry (LC-MS/MS).