Use this form for any tests your doctor recommends, such as blood tests, urine tests, or X-rays. General questions What is the name of the test? Why do I need this test? What might happen if the test is delayed or not done? How accurate is the test? Are there other tests that are more accurate? How much does the test...

A d-dimer test is a blood test that measures a substance that is released when a blood clot breaks up. Doctors order the d-dimer test, along with other lab tests and imaging scans, to help check for blood-clotting problems. A d-dimer test can also be used to check how well a treatment is working.

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 test (FIT). Guaiac fecal occult blood test (gFOBT). Stool DNA test, also...

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...

These are the tests you may need and how often you should have them. The tests may vary depending on whether you have type 1 or type 2 diabetes. A1c blood test. This test shows the average level of blood sugar over the past 2 to 3 months. It helps your doctor see whether blood sugar levels have been staying within your...

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...

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.

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.

A vitamin D test measures the amount of vitamin D in the blood. The vitamin D test is also called the 25-hydroxy vitamin D, or 25(OH)D, test. Your body needs vitamin D to absorb calcium. Calcium keeps your bones and muscles healthy and strong. If your muscles don't get enough calcium, they can cramp, hurt, or feel weak...

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...

The human chorionic gonadotropin (hCG) test is done to check for the hormone hCG in blood or urine. Some hCG tests measure the exact amount. Some just check to see if the hormone is present. HCG is made by the placenta during pregnancy. The test can be used to see if a woman is pregnant. HCG can be found in the blood...

Blood and urine are often tested to find the cause of health problems. But other body fluids also can be tested. Most of these fluids help organs and joints—and the membranes around them—move smoothly. Sometimes a health problem can cause too much fluid to build up in part of the body. The fluid can be tested to look...

During the first trimester of pregnancy, screening tests for birth defects may be done. These tests look for possible problems with your baby. The tests may be called first-trimester screening, combined first-trimester screening, or the combined screening. The screening tests show the chance of your baby having certain...

A sweat test, also called a sweat chloride test, measures the amount of chloride in sweat. It is done to help diagnose cystic fibrosis. Normally, sweat on the skin surface contains very little chloride. People with cystic fibrosis have a high level of chloride in their sweat. During the sweat test, medicine that causes...

Discusses oral glucose tolerance test that measures glucose (blood sugar) levels. Explains that test checks for gestational diabetes, prediabetes, and diabetes. Covers the types of tests done and how to prepare for them.

A C-reactive protein (CRP) test is a blood test that measures the amount of a protein called C-reactive protein in your blood. C-reactive protein measures general levels of inflammation in your body. High levels of CRP are caused by infections and many long-term diseases. But a CRP test cannot show where the...

Discusses prostate-specific antigen (PSA) test to measure amount of PSA in the blood. Explains that test is often used for cancer screening or follow-up. Covers how test is done and how to prepare for it. Discusses what results mean.

There are no specific tests that can confirm a diagnosis of fibromyalgia. But you may have lab tests to rule out other diseases. Or these tests can find out if you have another disease along with fibromyalgia. Fibromyalgia may occur along with other joint and muscle (rheumatic) diseases, such as rheumatoid arthritis...