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...

Discusses test used to check your heart and coronary arteries. Covers reasons cardiac catheterization is done. Looks at how to prepare. Explains how the test is done in the cardiac catheterization laboratory (cath lab) by a cardiologist. Covers risks.

A urine test checks different components of urine, a waste product made by the kidneys. It checks the color, clarity (clear or cloudy), odor, concentration, and acidity (pH) of your urine. It also checks your levels of protein, sugar, blood cells, or other substances in your urine. A urine test may be done to help find...

What is occupational asthma? Occupational asthma is the most common form of work-related lung disease in many countries. When a person gets asthma as an adult, exposure at work is a likely cause. This type of asthma happens when a person is exposed to certain substances in the workplace. Examples are wood dust...

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...

Provides overview of tests used to find out what a person might be allergic to. Covers skin and blood tests. Explains why and how each test is done. Discusses risks. Explains results and offers points to consider before having tests.

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...

Discusses stool analysis, a test used to look for bacteria, parasites, or blood in the digestive tract. Covers why and how it is done. Looks at risks. Covers normal and abnormal results.

A vitamin B12 test measures the amount of vitamin B12 in the blood. The body needs this B vitamin to make blood cells and to maintain a healthy nervous system. Vitamin B12 is found in animal products such as meat, shellfish, milk, cheese, and eggs. Most people who eat animal products are not likely to develop vitamin...

Discusses autism, an autism spectrum disorder (once known as a pervasive developmental disorder). Looks at signs of autism, including problems talking or repetitive behaviors. Covers behavioral and physical exams used to diagnose autism. Covers treatment options.

Guides you through the decision to have angioplasty when you have stable angina. Lists benefits and risks of angioplasty and medical therapy. Explains why lifestyle changes are still important. Includes interactive tool to help you with your decision.

Marine toxins are chemicals and bacteria that can contaminate certain types of seafood. Eating the seafood may result in food poisoning. The seafood may look, smell, and taste normal. There are five common types of marine toxins, and they all cause different symptoms. Food poisoning through marine toxins is rare. Marine...

A human papillomavirus (HPV) test is done to check for a high-risk HPV infection. Like a Pap test, an HPV test is done on a sample of cells collected from the cervix. HPV is a sexually transmitted infection (STI). An HPV test checks for the genetic material ( DNA) of the human papillomavirus. This test is used to show...

Dengue vaccine can help protect against dengue in people who have had dengue in the past. Dengue is caused by one of four viruses spread through the bite of an infected mosquito. A person can get infected by any of the four dengue viruses. Infection with one dengue virus does not protect...