Health Article description.Catecholamines (say "kat-uh-KOH-luh-meens") are hormones made mostly by your adrenal glands as a reaction to stress. When you feel stressed, these hormones increase heart rate, blood pressure, breathing rate, muscle strength, and mental alertness. They also lower the amount of blood that goes to the skin and intestines...

Health Article description.Fetal fibronectin is a protein that helps keep the amniotic sac attached to the wall of the uterus during pregnancy. If there is a problem with the amniotic sac staying attached to the uterus, high amounts of fetal fibronectin can end up in the vaginal fluid. This can mean there is an increased chance of having a...

Health Article description.A creatine kinase (CK) test checks the level of the enzyme creatine kinase, which is found in heart tissue and skeletal muscles. This enzyme also can be found in smaller amounts in the brain. A blood test to check the level of CK can show if there has been damage to the heart, skeletal muscles, brain, and sometimes...

Health Article description.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...

Health Article description.A cortisol test is done to measure the level of the hormone cortisol in the blood. The cortisol level may show problems with the adrenal glands or pituitary gland. Cortisol is made by the adrenal glands. Cortisol levels go up when the pituitary...

Health Article description.DHEA-S (dehydroepiandrosterone sulfate) is a male hormone (androgen) that is made in the adrenal glands. The body turns it into testosterone. A test for DHEA-S checks the level of this hormone in the blood. Testosterone affects sexual features and...

Health Article description.A growth hormone (GH) test measures the amount of human growth hormone (GH) in the blood. GH is made by the pituitary gland and is needed for growth. It plays an important role in how the body uses food for energy (metabolism). The amount of GH in...

Health Article description.A renin assay blood test is done to find the cause of high blood pressure (hypertension). Renin is an enzyme made by special cells in the kidneys. Renin works with aldosterone (a hormone made by the adrenal glands) and several other substances to help balance sodium and potassium levels in the blood and fluid levels in...

Health Article description.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...

Health Article description.A vitamin D test measures the amount of vitamin D in the blood. The vitamin D test is also called the 25-hydroxy vitamin D, or 25(OH)D, test. Your body needs vitamin D to absorb calcium. Calcium keeps your bones and muscles healthy and strong. If...

Health Article description.A bilirubin test measures the amount of bilirubin in a blood sample. Bilirubin is a brownish yellow substance found in bile. It is produced when the liver breaks down old red blood cells. Bilirubin is then removed from the body through the stool (feces) and gives stool its normal color. Bilirubin circulates in the...

Health Article description.The high-sensitivity C-reactive protein (hs-CRP) test is a blood test that finds lower levels of C-reactive protein (CRP). This protein measures general levels of inflammation in your body. The hs-CRP can be used to find the risk for heart disease and stroke in people who don't already have heart disease. The hs-CRP...

Health Article description.Discusses serum osmolality test used to check for dehydration, certain poisons, cause of seizures, and other problems. Covers how it is done and how to prepare for it. Also covers what test results may mean.

Health Article description.A lactic acid test is a blood test that measures the level of lactic acid made in the body. Most of it is made by muscle tissue and red blood cells. When the oxygen level in the body is normal, carbohydrate breaks down into water and carbon dioxide. When the oxygen level is low, carbohydrate breaks down for energy and...

Health Article description.Partial thromboplastin time (PTT) is a blood test that measures the time it takes your blood to clot. A PTT test can be used to check for bleeding problems. Blood clotting factors are needed for blood to clot (coagulation). The partial...

Health Article description.Laparoscopy (say "lap-uh-ROSS-kuh-pee") is a type of surgery that uses very small cuts in the belly. These cuts are called incisions. The doctor puts a lighted tube (scope) through an incision in your belly. Then the doctor puts special tools...

Health Article description.Explains why and how a test is done for galactosemia, a rare disease passed from parents to children. Covers blood or urine test that checks a newborn for enzymes needed to change galactose from milk into glucose.

Health Article description.A lipase test measures the amount of this enzyme in a blood sample. High amounts of lipase may be found in the blood when the pancreas is damaged or when the tube leading from the pancreas (pancreatic duct) to the beginning of the small intestine is blocked.

Health Article description.Prealbumin is a protein that is made in the liver and released in the blood. It helps carry certain hormones that regulate the way the body uses energy and other substances through the blood.

Health Article description.Explains liver biopsy, also called percutaneous liver biopsy, a test used to look for liver diseases like hepatitis, cirrhosis, hemochromatosis, and cancer. Covers how to prepare and what to expect. Includes what results mean. Also lists risks.

Health Article description.A testosterone test checks the level of this male hormone (androgen) in the blood. Testosterone affects sexual features and development. In men, it is made in large amounts by the testicles. In both men and women, testosterone is made in small...

Health Article description.Sperm penetration tests check to see if sperm can move through cervical mucus or join with (fertilize) an egg. These tests may be done when you're having trouble getting pregnant (infertility). There are different sperm penetration tests. The sperm...

Health Article description.Describes colonoscopy, a screening test that examines the lining of the large intestine. Explains that the test is done to look for polyps in the colon or rectum and to check for colorectal cancer. Discusses preparing for the test and how it is done.

Health Article description.Discusses blood glucose tests used to diagnose diabetes and prediabetes. Covers types of tests, including fasting blood sugar, 2-hour postprandial blood sugar, random blood sugar, and oral glucose tolerance. Discusses how to prepare and what results mean.

Health Article description.A prolactin test measures the level of the hormone prolactin, which is made by the pituitary gland, in your blood. Pregnant women have high levels of prolactin, which helps make breast milk. During pregnancy, prolactin levels increase by 10 to 20...