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. The U.S. Preventive Services Task Force recommends testing for prediabetes and type 2 diabetes in people who are overweight or obese and...

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...

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 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 ketones are made if your diet does not contain enough carbohydrates to...

An antinuclear antibody (ANA) test measures the amount and pattern of antibodies in your blood that work against your own body (autoimmune reaction). The body's immune system normally attacks and destroys foreign substances such as bacteria and viruses. But in disorders known as autoimmune diseases, the immune system...

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 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 amounts by the adrenal glands, and in women, by the ovaries. The pituitary...

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 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...

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 nerves and muscles work. Most of the sodium in the body is found in blood...

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 times. After the baby is born, prolactin stays high if you are...

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 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...

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...

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...

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...

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...

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...

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.

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 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...

A viral load test measures how much HIV is in the blood. It's first measured when you're diagnosed with HIV. This serves as the baseline. Future measurements are compared with it. With treatment, the viral load should go down. Within a few months, there should be very little virus in your blood.

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.