Health Article description.Covers test done on a kidney stone to find out what the stone is made of. Links to info on types of stones, including calcium, uric acid, struvite, and cystine. Explains that test can help doctor decide treatment or give info on preventing more stones from forming.

Health Article description.A sweat test, also called a sweat chloride test, measures the amount of chloride in sweat. It is done to help diagnose cystic fibrosis. Normally, sweat on the skin surface contains very little chloride. People with cystic fibrosis have a high level...

Health Article description.Discusses blood test to check the different types of hemoglobin in the blood. Covers how some diseases, such as sickle cell disease, aplastic anemia, and leukemia, have abnormal types of hemoglobin. Discusses possible test results.

Health Article description.Creatinine and creatinine clearance tests measure the level of the waste product creatinine (say "kree-AT-uh-neen") in your blood and urine. These tests tell how well your kidneys are working. Another substance, creatine (say "KREE-uh-teen"), is...

Health Article description.A spinal tap (also called a lumbar puncture) is a procedure to collect and look at the fluid ( cerebrospinal fluid, or CSF) that surrounds the brain and spinal cord. During a spinal tap, a needle is carefully inserted into the spinal canal low in the back (lumbar area). Samples of CSF are collected. The samples are...

Health Article description.A luteinizing hormone test measures the amount of luteinizing hormone (LH) in a sample of blood or urine. LH is produced by the pituitary gland. LH helps regulate the menstrual cycle and egg production ( ovulation). LH levels normally change with the phase of the menstrual cycle. This hormone goes up fast just before...

Health Article description.Covers why and how parathyroid hormone tests are done. Covers what possible results might mean. Includes info on what might affect the test.

Health Article description.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...

Health Article description.A gastrin test measures the level of the hormone gastrin in the blood. Gastrin is produced by cells, called G cells, in the stomach lining. When food enters the stomach, G cells trigger the release of gastrin in the blood. As blood levels of gastrin rise, the stomach releases acid (gastric acid) that helps break down...

Health Article description.The carcinoembryonic antigen (CEA) test measures the amount of this protein that may appear in the blood of some people who have certain kinds of cancers, especially cancer of the large intestine (colon and rectal cancer). It may also be present in...

Health Article description.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...

Health Article description.Cardiac enzyme studies measure the levels of enzymes and proteins that are linked with injury of the heart muscle. The test checks for the proteins troponin I (TnI) and troponin T (TnT). If your heart muscle is injured, such as from a heart attack,

Health Article description.Doctors are experts on medical care. But you are the expert on yourself and your life. That's why it's important to be an active patient. When you're actively involved in decisions about your care, you can be sure that your choices reflect your...

Health Article description.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...

Health Article description.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...

Health Article description.Getting great care at a lower price is possible. Just like when you shop for food or clothes, there are things you can do to lower your health care costs. Here are some things you can do to take charge of your health and lower your health care costs.

Health Article description.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...

Health Article description.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...

Health Article description.Discusses toxoplasmosis test, a blood test that checks pregnant women for antibodies to the Toxoplasma gondii parasite. Covers why and how it is done. Also discusses what results mean.

Health Article description.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.

Health Article description.What is chronic myeloid leukemia (CML)? Chronic myeloid leukemia (CML) is type of cancer in which the bone marrow makes too many white blood cells. In CML, young white blood cells grow abnormally, and they don't mature or die off as they should. These abnormal cells can crowd out normal blood cells and cause problems...

Health Article description.Use this form for any tests your doctor recommends, such as blood tests, urine tests, or X-rays. General questions What is the name of the test? Why do I need this test? What might happen if the test is delayed or not done? How accurate is the test? Are there other tests that are more accurate? How much does the test...

Health Article description.Has info on finger, hand, and wrist problems as well as shoulder injuries. Also has info on osteoarthritis and fibromyalgia with links to low back pain exercises and info on tennis elbow surgery.

Health Article description.Education on type 1 diabetes, type 2 diabetes, and gestational diabetes. Includes info on juvenile diabetes and prediabetes. Discusses symptoms and treatment. Also looks at how to manage blood sugar levels, diet, and medicines, including insulin.

Health Article description.Discusses chronic pain caused by problems other than cancer. Covers symptoms and how chronic pain is diagnosed. Covers conditions that can be treated, like neck pain, low back pain, and arthritis. Info on treatment with medicine and lifestyle changes.