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.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...

Health Article description.An amylase test measures the amount of this enzyme in a sample of blood taken from a vein or in a sample of urine. Normally, only low levels of amylase are found in the blood or urine. But if the pancreas or salivary glands become damaged or blocked, more amylase is usually released into the blood and urine. In the...

Health Article description.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.

Health Article description.It's important to take care of your supplies so that you can test your blood sugar safely and get the most accurate results. Take care of your meter. Follow the care instructions from the manufacturer. Some meters need to be cleaned regularly and have their batteries changed now and then. Meters can be damaged if...

Health Article description.Doctors follow guidelines from experts to decide when to test adults for type 2 diabetes. Talk with your doctor about your risk for type 2 diabetes and how often you need to be tested. Testing involves a blood test that is simple and usually very...

Health Article description.The D-xylose absorption test measures the level of D-xylose, a type of sugar, in a blood or urine sample. This test is done to help diagnose problems that prevent the small intestine from absorbing nutrients in food. D-xylose is normally easily...

Health Article description.The guaiac fecal occult blood test (gFOBT) is used to screen for colorectal cancer. Cancer in the colon or polyps in the colon are more likely to bleed than normal colon tissue is. This test uses a chemical to check for very small amounts of blood in the stool. If signs of blood are found in the stool sample, more...

Health Article description.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...

Health Article description.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...

Health Article description.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.

Health Article description.Hemochromatosis gene (HFE) testing is a blood test used to check for hereditary hemochromatosis, an inherited disorder that causes the body to absorb too much iron. The iron then builds up in the blood, liver, heart, pancreas, joints, skin, and other organs. In its early stages, hemochromatosis can cause joint and belly...

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.An aldosterone test measures the level of aldosterone (a hormone made by the adrenal glands), in the blood. Aldosterone helps regulate sodium and potassium levels in the body. This helps control blood pressure and the balance of fluids and...

Health Article description.Lab tests play an important role in your health care. They help your doctor make a diagnosis or treatment decisions. But they may not provide all of the information that your doctor needs. Your doctor will not usually make a decision or diagnosis based only on the results of a lab test, unless the test results are...

Health Article description.Has links on complete blood count, sedimentation rate tests, and anemia. Also includes links to lymph topics such as swollen glands/other lumps under the skin and lymphedema.

Health Article description.A toxicology test ("tox screen") checks for drugs or other chemicals in your blood, urine, or saliva. In rare cases, a tox screen may check your stomach contents or sweat. Drugs can be swallowed, inhaled, injected, or absorbed through the skin or a...

Health Article description.A sodium test checks how much sodium is in the blood. Sodium is both an electrolyte and 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...

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.A ketone test checks for ketones in your blood or urine. Ketones are substances that are made when the body breaks down fat for energy. Normally, your body gets the energy it needs from carbohydrate in your diet. But stored fat is broken down and...

Health Article description.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...

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...