Doctor-Reviewed Health Guides: Conditions, Procedures & Health News

A chloride blood test measures the amount of chloride, an electrolyte, in the blood. Chloride helps control nerve and muscle function, acid-base balance and the body's water. A normal adult level is about 96 to 106 mEq/L; high levels can point to dehydration or kidney disease, and low levels to heart failure or certain lung conditions.

Fluoroscopy is an imaging method that uses a series of quick X-ray pulses to show the inside of the body moving in real time, like a video. Providers use it to diagnose problems with organs and to guide procedures like placing a catheter or stent. The main risk is radiation exposure, which is very low for diagnostic exams.

A transthoracic echocardiogram (TTE) is the most common type of echocardiogram. It uses sound waves from a wand moved across the chest to create moving pictures of the heart's chambers, valves and nearby blood vessels. It shows how well the heart pumps and helps diagnose heart failure and valve disease. It takes about an hour and uses no radiation.

A sleep study, or polysomnogram, is a painless overnight test that records several body systems while you sleep, including brain waves, eye and muscle movements, heart rhythm, breathing and blood oxygen. It helps diagnose sleep disorders such as obstructive sleep apnea, narcolepsy, restless legs and insomnia. Most studies take one night in a sleep lab.

Blood alcohol content (BAC) is the amount of alcohol in your blood. It ranges from 0%, meaning no alcohol, to over 0.4%, a level that can be fatal. A BAC blood test is used to diagnose alcohol poisoning and for workplace and legal testing, and the blood draw usually takes less than five minutes.

Cytology, also called cytopathology, is a test in which a pathologist looks at cells from a sample of tissue or body fluid under a microscope. It checks for changes in the size, shape or other features of cells. It's used most often to screen for or diagnose cancer and precancerous changes, but it can find infections and inflammatory conditions.

A fasting blood sugar test is a blood test that measures the sugar (glucose) in the blood after 8 to 12 hours without food or drink other than water. It screens for diabetes, prediabetes and gestational diabetes. A result below 100 mg/dL is normal, 100 to 125 mg/dL points to prediabetes, and 126 mg/dL or higher points to diabetes.

A D-dimer test is a blood test that measures D-dimer, a protein fragment your body releases when a blood clot breaks down. Levels are normally very low or undetectable. A normal result most likely means you do not have a clotting disorder, while a high result means you may need more tests, usually imaging, to find out why.

A hearing test, also called audiometry, is the main way to find out whether you have hearing loss, what type it is and how mild or severe it is. An audiologist uses painless tests such as pure-tone, speech and bone conduction testing, often with headphones. Results are ready right away and are shown on a chart called an audiogram.

A prostate exam is a screening check for early signs of prostate cancer, usually made up of a PSA blood test and a digital rectal exam (DRE). It's typically offered starting by age 50, or earlier if you have a higher risk. An abnormal result does not mean you have cancer, but you need more tests.

Flow cytometry is a laser-based lab test that looks at the physical and chemical features of cells in a sample of blood, bone marrow, tissue or other body fluid. Providers use it to count and sort immune cells and to identify cancer cells, especially in leukemia and lymphoma. Results usually take several days to a week.

A CO2 blood test measures your level of bicarbonate, which shows how much carbon dioxide (CO2) is in your blood. It is often done as part of an electrolyte panel. A standard level is 20 to 29 mmol/L, and a result outside this range may point to a problem with your kidneys or lungs.

An electrocardiogram, also called an EKG or ECG, is a quick, noninvasive test that records your heart's electrical activity. Providers use it to find rhythm problems, check on heart conditions and see how well a treatment is working. A resting test takes about 10 minutes, the recording itself takes about 10 seconds, and you feel nothing while it runs.

A urinalysis is a set of tests on a sample of your urine. It looks at how your urine appears, checks it with a chemical dipstick and may examine it under a microscope for cells, crystals and germs. Providers use it for routine checkups and to look for infection, kidney or liver disease, diabetes and other conditions.

An albumin blood test measures the amount of albumin, a protein made by your liver, in your blood. Providers use it to check how well your liver and kidneys are working, and it can also point to nutrition problems. A normal adult level is 3.5 to 5.5 grams per deciliter (g/dL), and the blood draw takes only a few minutes.

A spine X-ray is a quick imaging test that uses a small dose of radiation to take pictures of the bones (vertebrae) in the neck and back. It helps find the cause of neck or back pain and can reveal fractures, arthritis, osteoporosis and spinal curves such as scoliosis. It takes about 15 minutes and needs no preparation.

A DOT physical is a medical exam that shows whether you meet federal health standards to safely drive a commercial motor vehicle. A certified medical examiner reviews your health history and checks your vision, hearing, blood pressure, urine, heart and lungs. If you pass, you receive a medical certificate that is usually valid for two years.

Amniocentesis is a prenatal test in which a provider uses a thin needle, guided by ultrasound, to take a sample of the amniotic fluid around the fetus. A lab checks fetal cells in that fluid for genetic and chromosome conditions. It's usually done between 15 and 20 weeks of pregnancy, takes about 30 minutes and is about 99% accurate.

Blood tests are lab tests that measure or examine parts of the blood, such as red and white blood cells, platelets, electrolytes, proteins, hormones and minerals. They're used during routine checkups, to screen for risk factors, to look into symptoms and to see whether a treatment is working. A single abnormal number is not a diagnosis on its own.

Magnetic resonance cholangiopancreatography (MRCP) is a type of MRI scan that creates detailed pictures of the bile ducts, gallbladder and pancreas. It uses a magnetic field and radio waves instead of X-rays. Providers order it to check for gallstones, blocked or narrowed ducts, pancreatitis, cysts and tumors. The scan takes about 15 minutes and does not involve an endoscope.

A heart MRI, or cardiac MRI, is a noninvasive scan that uses a strong magnet and radio waves, not radiation, to make detailed pictures of the heart. It shows the heart's chambers, valves and muscle and how well they work. It takes 30 minutes to 1.5 hours.

Capsule endoscopy is a test in which you swallow a pill-sized capsule that holds a tiny camera and light. As it travels through the digestive tract, it takes thousands of pictures, mainly of the small intestine, and sends them to a recorder you wear. It's painless, and the capsule leaves the body in the stool, usually within 24 hours.

The Child-Pugh score is a scoring system that rates how severe chronic liver disease is, most often cirrhosis. It adds up points for five factors: bilirubin, albumin, clotting time, ascites and hepatic encephalopathy. Each factor scores 1 to 3 points, for a total of 5 to 15, which places you in class A, B or C.

Fluorescein angiography is an eye imaging test that photographs the blood vessels of the retina. An eye specialist widens your pupils with drops, injects a fluorescent dye into a vein and takes pictures as the dye flows through the eye. It takes less than 30 minutes, is low risk and helps diagnose diabetic retinopathy and macular degeneration.