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...

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.

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...

A spinal tap (also called a lumbar puncture) is a procedure to collect and look at the fluid ( cerebrospinal fluid, or CSF) that surrounds the brain and spinal cord. During a spinal tap, a needle is carefully inserted into the spinal canal low in the back (lumbar area). Samples of CSF are collected. The samples are...

An aldosterone test measures the level of aldosterone (a hormone made by the adrenal glands) in the urine. Aldosterone helps regulate sodium and potassium levels in the body. This helps control blood pressure and the balance of fluids and electrolytes in the blood. The kidney hormone renin normally stimulates the...

A cortisol test measures the level of the hormone cortisol in a 24-hour sample of urine. The cortisol level may show problems with the adrenal glands or the pituitary gland. Cortisol is made by the adrenal glands. Cortisol levels get higher when...

Paracentesis is a procedure to take out fluid that has collected in the belly ( peritoneal fluid) outside the intestines. This fluid buildup is called ascites. Ascites may be caused by infection, inflammation, an injury, or other conditions, such as cirrhosis or cancer. The fluid is taken out using a thin needle put...

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...

Bronchoscopy is a procedure that allows your doctor to look at your airway through a thin viewing device called a bronchoscope. During a bronchoscopy, your doctor will examine your throat, larynx, trachea, and lower airways. This procedure may be...

An electrophysiology study, or EP study, is a test to see if there is a problem with your heartbeat (heart rhythm) and to find out how to fix it. In this test, the doctor inserts flexible tubes called catheters into blood vessels. These blood vessels are typically in the groin or neck. Then the doctor threads these...

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...

A filling is a material that your dentist uses to fill a cavity after the dentist removes any tooth decay. To fill a tooth, your dentist will numb the area, drill out the decay, and put in a filling. There are many types of fillings. Types of fillings Fillings can be made from many types of material. Talk to your...

What is colic? All babies cry, but sometimes a baby will cry for hours at a time, no matter what you do. This extreme type of crying in a baby between 3 weeks and 3 months of age is called colic. Although it is upsetting for parents and caregivers, colic is normal for some babies. Doctors usually diagnose colic when a...