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...

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...

A chloride test measures the level of chloride in your blood or urine. Chloride is one of the most important electrolytes in the blood. It helps keep the amount of fluid inside and outside of your cells in balance. It also helps maintain proper blood volume, blood pressure, and pH of your body fluids. Tests for sodium...

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.

Discusses blood urea nitrogen (BUN) test. Covers why and how it is done. Includes how to prepare for the test. Covers risks. Explains results of the test. Covers what affects results.

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...

A chemistry screen is a blood test that measures the levels of several substances in the blood (such as electrolytes). A chemistry screen tells your doctor about your general health, helps look for certain problems, and finds out whether treatment for a specific problem is working. Some chemistry screens look at more...

A magnesium test checks the level of magnesium in the blood. Magnesium is an important electrolyte needed for proper muscle, nerve, and enzyme function. It also helps the body use energy and is needed to move other electrolytes (potassium and sodium) into and out of cells. Most of the magnesium in the body is found in...

A folate test measures the amount of folate in the blood. Folate is one of many B vitamins. The body needs folate for normal growth and to make red blood cells (RBC), white blood cells (WBC), and platelets. Folate also is important for the normal development of a baby (fetus). Folate can be measured in the liquid...

An iron test checks the amount of iron in the blood. Iron (Fe) is a mineral needed for hemoglobin, the protein in red blood cells that carries oxygen. Iron is also needed for energy, good muscle, and organ function. About 70% of the body's iron is bound to hemoglobin in red blood cells. The rest is bound to other...

An alpha-fetoprotein (AFP) blood test checks the level of AFP in a pregnant woman's blood. AFP is a substance made in the liver of an unborn baby (fetus). The amount of AFP in the blood of a pregnant woman can help see whether the baby may have such problems as spina bifida and anencephaly. An AFP test can also be done...

Myoglobin is a protein found in heart tissue and other muscles. It is released into the blood after damage to the heart or other muscles. Damage can occur from a serious event such as a heart attack or a burn. Myoglobin can be checked with a blood test or a urine test.

Discusses cancer antigen 125 (CA-125) test that can help show if some types of cancer are present. Covers its use to check how well treatment for ovarian cancer is working or to see if ovarian cancer has returned. Covers possible test results.

An arterial blood gases (ABG) test measures the acidity ( pH) and the levels of oxygen and carbon dioxide in the blood from an artery. This test is used to find out how well your lungs are able to move oxygen into the blood and remove carbon dioxide from the blood. As blood passes through your lungs, oxygen moves into...

A test for calcium in urine is a 24-hour test that checks the amount of calcium that is passed from the body in the urine. Calcium is the most common mineral in the body and one of the most important. The body needs it to build and fix bones and teeth, help nerves work, make muscles squeeze together, help blood clot...

A progesterone test measures the amount of the hormone progesterone in a blood sample. Progesterone is a hormone produced by the ovaries during release of a mature egg from an ovary (ovulation). Progesterone helps prepare the lining of the uterus (endometrium) to receive the egg if it becomes fertilized by a sperm. If...

A follicle-stimulating hormone test measures the amount of follicle-stimulating hormone (FSH) in a blood sample. FSH is produced by the pituitary gland. FSH helps control the menstrual cycle and the production of eggs by the ovaries. FSH also helps control the production of sperm. The amount of FSH varies throughout the...

Looks at homocysteine as a test to measure homocysteine in the blood. Covers how test is done and what results mean. Explains what could affect results.

A phosphate test measures the amount of phosphate in a blood sample. Phosphate is a charged particle (ion) that contains the mineral phosphorus. The body needs phosphorus to build and repair bones and teeth, help nerves function, and make muscles contract. Most (about 85%) of the phosphorus contained in phosphate is...

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...

A test for sodium in the urine is a 24-hour test or a one-time (spot) test that checks for how much sodium is in the urine. Sodium is both an electrolyte and a mineral. It helps keep the water (the amount of fluid inside and outside the body's cells) and electrolyte balance of the body. Sodium is also important in how...

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 immunoglobulins test is done to measure the level of immunoglobulins, also known as antibodies, in your blood. Antibodies are substances made by the body's immune system in response to bacteria, viruses, fungus, animal dander, or cancer cells. Antibodies attach to the foreign substances so the immune system can...

The phosphate urine test measures the amount of phosphate in a sample of urine collected over 24 hours (24-hour urine test). Phosphate is a charged particle (ion) that contains the mineral phosphorus. The body needs phosphorus to build and repair bones and teeth, help nerves function, and make muscles contract. Most...

Guides you through choosing a test to check for colorectal cancer. Looks at symptoms of colorectal cancer. Covers stool tests, sigmoidoscopy, colonoscopy, and virtual colonoscopy. Includes interactive tool to help you make your decision.