Prothrombin time (PT) is a blood test that measures how long it takes blood to clot. A prothrombin time test can be used to check for bleeding problems. PT is also used to check whether medicine to prevent blood clots is working. A PT test may also be called an INR test. INR (international normalized ratio) stands for a...

A total serum protein test measures the total amount of protein in the blood. It also measures the amounts of two major groups of proteins in the blood: albumin and globulin. Albumin. This is made mainly in the liver. It helps keep the blood from leaking out of blood vessels. Albumin also helps carry some medicines and...

Discusses a test that checks urine for a protein called albumin. Covers possible kidney damage and diabetes. Explains how test is done. Discusses normal and abnormal values from the test. Covers what affects the test.

Looks at various tests used to check how well the thyroid gland is working. Covers what results might mean. Also looks at what might affect a test. Offers links to info on other tests that might be useful, including thyroid-stimulating hormone (TSH) test.

A stool test is one of many tests used to look for colorectal cancer. Colorectal cancer affects the large intestine (colon) and the rectum. Stool tests look for signs of blood or cancer in a stool sample. Stool tests include: Fecal immunochemical...

The blood uric acid test measures the amount of uric acid in a blood sample. Uric acid is produced from the natural breakdown of your body's cells and from the foods you eat. Most of the uric acid is filtered out by the kidneys and passes out of the body in urine. A small amount passes out of the body in stool. But if...

Thyroid antibody tests measure the levels of antibodies that can destroy thyroid tissue or make the cells produce thyroid hormones. They are blood tests. Antibodies that destroy thyroid tissue can lead to hypothyroidism (underactive thyroid). Antibodies that make the cells produce thyroid hormone can lead to...

The uric acid urine test measures the amount of uric acid in a sample of urine collected over 24 hours. Uric acid is made from the natural breakdown of your body's cells. It's also made from the foods you eat. Your kidneys take uric acid out of your blood and put it into urine so that it can leave your body. But if your...

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...

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.

The sedimentation rate (sed rate) blood test measures how quickly red blood cells (erythrocytes) settle in a test tube in one hour. The more red cells that fall to the bottom of the test tube in one hour, the higher the sed rate. When inflammation is present in the body, certain proteins cause red blood cells to stick...

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 test for calcium in the blood checks the calcium level in the body that is not stored in the bones. 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, and help the heart to...

Discusses C-peptide test, used to tell the difference between type 1 and type 2 diabetes, find the cause of hypoglycemia, or check whether a pancreas tumor (insulinoma) was completely removed. Discusses how the test is done and how to prepare for it.

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...

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...

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...