Discusses test to help diagnose lung disease, lymphoma, anemia, liver disease, and also to see how well chemotherapy is working during treatment for lymphoma. Looks at possible results.

A rheumatoid factor (RF) blood test measures the amount of the RF antibody present in the blood. Normally, antibodies are produced by the immune system to help destroy and get rid of invading bacteria and viruses that can cause disease. But the RF...

A rubella blood test detects antibodies that are made by the immune system to help kill the rubella virus. These antibodies remain in the bloodstream for years. The presence of certain antibodies means a recent infection, a past infection, or that you have been vaccinated against the disease. Rubella (also called German...

Vision is the result of electrical signals that travel between the retina and the part of the brain involved with vision (occipital cortex). Electrophysiology tests check to see how well this visual nerve pathway sends the electrical signals needed for vision. These tests measure electrical activity that occurs in your...

An aldosterone test measures the level of aldosterone (a hormone made by the adrenal glands) in the urine. Aldosterone helps regulate sodium and potassium levels in the body. This helps control blood pressure and the balance of fluids and electrolytes in the blood. The kidney hormone renin normally stimulates the...

A cortisol test measures the level of the hormone cortisol in a 24-hour sample of urine. The cortisol level may show problems with the adrenal glands or the pituitary gland. Cortisol is made by the adrenal glands. Cortisol levels get higher when the pituitary gland releases adrenocorticotropic hormone (ACTH). Cortisol...

An aspartate aminotransferase (AST) test measures the amount of this enzyme in the blood. AST is normally found in red blood cells, liver, heart, muscle tissue, pancreas, and kidneys. AST formerly was called serum glutamic oxaloacetic transaminase (SGOT). Low levels of AST are normally found in the blood. When body...

A ferritin blood test checks the amount of ferritin in the blood. Ferritin is a protein in the body that binds to iron; most of the iron stored in the body is bound to ferritin. Ferritin is found in the liver, spleen, skeletal muscles, and bone marrow. Only a small amount of ferritin is found in the blood. The amount of...

An alkaline phosphatase (ALP) test measures the amount of the enzyme ALP in the blood. ALP is made mostly in the liver and in bone with some made in the intestines and kidneys. It also is made by the placenta during pregnancy. The liver makes more ALP than the other organs or the bones. Some conditions cause large...

An estrogen test measures the level of the most important estrogen hormones in a blood or urine sample. It measures estradiol, estriol, and estrone. Estradiol is the most common type of estrogen measured for nonpregnant women. The amount of estradiol in a woman's blood varies throughout her menstrual cycle. After...

A cold agglutinins blood test is done to check for conditions that cause the body to make certain types of antibodies called cold agglutinins. Cold agglutinins are normally made by the immune system in response to infection. They cause red blood cells to clump together (agglutinate) at low temperatures. Healthy people...

An alanine aminotransferase (ALT) test measures the amount of this enzyme in the blood. ALT is found mainly in the liver, but also in smaller amounts in the kidneys, heart, muscles, and pancreas. ALT was formerly called serum glutamic pyruvic transaminase (SGPT). ALT is measured to see if the liver is damaged or...

An ammonia test measures the amount of ammonia in the blood. Most ammonia in the body forms when protein is broken down by bacteria in the intestines. The liver normally converts ammonia into urea, which is then eliminated in urine. Ammonia levels in the blood rise when the liver is not able to convert ammonia to urea...

The serum protein electrophoresis (SPEP) test measures specific proteins in the blood to help identify some diseases. Proteins are substances made up of smaller building blocks called amino acids. Proteins carry a positive or a negative electrical charge, and they move in fluid when placed in an electrical field. Serum...

A test for catecholamines measures the amount of the hormones epinephrine, norepinephrine, and dopamine in the blood. These catecholamines are made by nerve tissue, the brain, and the adrenal glands. Catecholamines help the body respond to stress or fright and prepare the body for "fight-or-flight" reactions. The...

An adrenocorticotropic hormone test measures the level of adrenocorticotropic hormone (ACTH) in the blood to check for problems with the pituitary gland and adrenal glands. ACTH is made in the pituitary gland in response to the release of another hormone, called corticotropin-releasing hormone (CRH), by the...

Anoscopy, proctoscopy, and sigmoidoscopy tests allow your doctor to look at the inner lining of your anus, your rectum, and the lower part of the large intestine (colon). These tests are used to look for abnormal growths (such as tumors or polyps), inflammation, bleeding, hemorrhoids, and other conditions (such as...

Provides links that give tips, like making the most of your appointment and getting better care at lower costs. Also includes links on understanding lab results and deciding whether to get a flu vaccine.

Outpatient services are medical procedures, surgeries, therapies, classes, or tests that are done in a qualified medical center without the need for an overnight stay. In general, outpatient centers focus on services for wellness and prevention, diagnosis, treatment, and rehabilitation. In these centers, a person may...

Describes pancreatic cancer. Talks about symptoms and what tests are used to diagnose it. Provides treatment details. Lists factors that raise your risk.

Describes various sleep studies used to diagnose sleep disorders. Discusses problems like snoring, sleep apnea, insomnia, and narcolepsy. Covers common sleep studies, including polysomnograms, multiple sleep latency tests, and the maintenance of wakefulness test.

At each prenatal visit during your first trimester, you'll be weighed and have your blood pressure checked. Your urine may also be checked for bacteria, protein, or sugar. As early as weeks 10 to 12, you may be able to hear your baby's heartbeat...

A doctor diagnoses mild, or subclinical, hypothyroidism through a medical history and physical exam. If your doctor suspects that you have subclinical hypothyroidism, you will have lab tests to confirm the diagnosis. Subclinical hypothyroidism is...

Clopidogrel (Plavix) is a medicine to prevent blood clots, which can cause heart attacks and strokes. It may be prescribed after a heart attack, after angioplasty, and for people who have coronary artery disease or peripheral arterial disease. Some...