Health Library

The Health Library is a collection of health and wellness resources created for learning and accessibility. Select a topic below for related health information or search for a topic in the search bar for more information on other medical conditions.

Findings and Diagnosis

  • A blood alcohol test measures the amount of alcohol (ethanol) in your body. Alcohol is quickly absorbed into the blood and can be measured within minutes of having an alcoholic drink. The amount of alcohol in the blood reaches its highest level about an hour after drinking. But food in the stomach may increase the...

  • Knowing the stage and grade of a person's cancer helps doctors know what treatment to use. It also helps predict how long the person will survive or whether there is a good chance for a cure. Staging is a way to describe how much cancer is in the body and where it is located. If the cancer has spread, staging also...

  • Experts on digestive diseases developed these criteria, known as the Rome III criteria, to help doctors determine whether symptoms are caused by irritable bowel syndrome (IBS). You meet the Rome III criteria for IBS if your symptoms began at least 6...

  • To be diagnosed with diabetes, you must meet one of the following criteria: Have symptoms of diabetes (increased thirst, increased urination, and unexplained weight loss) and a blood sugar level equal to or greater than 200 milligrams per...

  • Sleep apnea occurs when you regularly stop breathing for 10 seconds or longer during sleep. It can be mild, moderate, or severe, based on the number of times an hour that you stop breathing (apnea) or that airflow to your lungs is reduced (hypopnea). This is called the apnea-hypopnea index (AHI)...

  • Syphilis is described in terms of its four stages: primary, secondary, latent (hidden), and tertiary (late). Primary stage During the primary stage, a sore ( chancre) that is usually painless develops at the site where the bacteria entered the body. This commonly occurs within 3 weeks of exposure but can...

  • The American College of Cardiology and the American Heart Association have devised a classification system for heart failure. It categorizes heart failure based on how the disease progresses in most people. Under this system, heart failure is...

  • Lyme disease can go through several stages. It may cause different symptoms, depending on how long you have been infected and where in your body the infection has spread. Stage 1: Early localized Lyme disease (1 to 4 weeks) Early localized Lyme disease develops days to weeks after you become infected. You may have...

  • You can quickly estimate the size of a burn by using the "rule of nines." This method divides the body's surface area into percentages. Estimating burn size in adults See a picture of the "rule of nines" for adults. The front and back of the head and neck equal 9% of the body's surface area. The front and back of...

  • Lab test results usually contain some type of unit of measurement. The units provide a way to report results so that they can be compared. Usually, but not always, the same test is reported in the same units no matter which lab did the test. Units...

  • Lab tests play one role in your health care. But while it is an important role, in most cases lab tests don't provide all the information your doctor needs to make a diagnosis or treatment decisions. Unless the test results are clear—either you are pregnant or you're not—your doctor will rarely make a decision or...

  • A tumor marker is a substance released by cancer cells or by normal cells when cancer is in the body. Tumor markers can be hormones, proteins, enzymes, or other substances. Some conditions that are benign (not cancer) also release tumor markers....

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