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...

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...

Syphilis tests are done to check for a syphilis infection. They look for antibodies to the bacteria that cause syphilis. Some tests look for the syphilis bacteria. Syphilis is a sexually transmitted infection. That means it is spread through sexual contact: vaginal, anal, or oral sex. It can also spread to the fetus of...

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...

Helicobacter pylori tests are used to detect a Helicobacter pylori ( H. pylori) infection in the stomach and upper part of the small intestine ( duodenum). H. pylori can cause peptic ulcers. But most people with H. pylori in their digestive systems do not develop ulcers. Four tests are used to detect H. pylori: Blood...

A test for catecholamines measures the amount of the hormones epinephrine, norepinephrine, and dopamine in the blood. These catecholamines are made by nerve tissue, the brain, and the adrenal glands. Catecholamines help the body respond to stress or fright and prepare the body for "fight-or-flight" reactions. The...

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 gland releases another hormone called adrenocorticotropic hormone (ACTH)...

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.

What is Rh sensitization during pregnancy? You may have Rh-negative blood, and your baby may have Rh-positive blood. If the two types of blood mix, your body will make antibodies. This is called Rh sensitization. In most cases, this isn't a problem the first time you're pregnant. But in future pregnancies, sensitization...

Describes monitoring blood sugar levels in those with diabetes. Gives step-by-step instructions. Covers how to record testing results and how to prevent sore fingers.

Discusses blood test used to check for thyroid gland problems. Explains how TSH causes thyroid gland to make hormones that help control metabolism. Covers how it is done and test results.

Covers blood test that checks the amount of sugar (glucose) bound to hemoglobin. Explains that test is done to check how well you are managing your diabetes. Covers how it is done and discusses results.

Describes monitoring blood sugar levels in children with diabetes. Gives step-by-step instructions. Covers how to record testing results and how to prevent sore fingers.

Covers screening tests, diagnostic tests, and medical exams used to find a disease or determine risk for certain health problems. Covers well-child visits. Includes links to info on routine tests for men, for women, and at various stages of life.

Covers causes and symptoms of high blood pressure. Explains systolic and diastolic pressure numbers. Looks at treatment and prevention steps. Includes risks of untreated high blood pressure such as heart attack, stroke, and kidney failure.

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...

Carbon dioxide (CO2) is a gaseous waste product from metabolism. The blood carries carbon dioxide to your lungs, where it is exhaled. More than 90% of it in your blood exists in the form of bicarbonate (HCO3). The rest of it is either dissolved carbon dioxide gas (CO2) or carbonic acid (H2CO3). Your kidneys and lungs...

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.

Learn what to expect when you have a blood test.

Birth defects testing is done during pregnancy to look for possible problems with the baby (fetus). A birth defect may have only a minor impact on a child's life. Or it can have a major effect on quality or length of life. You and your doctor can...

Covers type 1 diabetes in children. Includes info on managing diabetes. Discusses using glucose monitors for blood glucose testing. Includes links to info on dealing with diabetes in school. Includes info on hypoglycemia and hyperglycemia.

Covers iron deficiency anemia. Explains role of iron in making hemoglobin, part of red blood cells. Covers causes and symptoms. Includes info on tests used to diagnose anemia. Discusses foods that may help prevent anemia. Covers treatment with medicines.

Provides info on an initial diagnosis. Discusses diagnostic tests, including PSA test and digital rectal exam. Covers symptoms common to prostate cancer and other conditions. Discusses treatment with active surveillance, surgery, or radiation. Also offers prevention tips.

Guides through decision to have a PSA test to check for prostate cancer. Includes what PSA results tell you and what they do not. Covers benefits and risks. Includes an interactive tool to help you decide.

Discusses testing and diagnosis of colorectal cancer. Covers polyps, small growths inside the colon or rectum. Includes when screening tests such as colonoscopy should be done. Discusses treatment with surgery and chemotherapy. Offers prevention tips.