What is it?
The human body turns food into fuel or sugars, known as glucose. Diabetes is a disease in which the body can't maintain normal glucose levels on its own, meaning the pancreas is unable to create an essential hormone called insulin.
Some people with diabetes can't produce insulin at all; others have bodies that struggle to use the insulin healthfully. In either case, untreated diabetes means sugar builds up in the blood.
More than 90 percent of the 25 million Americans with the disease have Type 2 diabetes. Another 79 million are estimated to have pre-diabetes.
Symptoms can include intense thirst, excessive urination, exhaustion, unexplained weight loss, extreme hunger, sudden vision changes, tingling or numbness in hands or feet, and sores that are slow to heal.
Diabetes, the seventh-leading cause of death for Americans, has severe consequences if not treated properly. It can lead to heart disease, blindness, kidney failure and lower-extremity amputations.
What it means:
Type 1 diabetes: Known as insulin-dependent diabetes, it involves the body producing insufficient insulin, resulting in abnormal metabolism of carbohydrates, fats and proteins. Insulin must be injected to regulate blood sugar levels.
Type 2 diabetes: An inactive lifestyle and obesity exacerbate the body's ability to tolerate glucose.
Pre-diabetes: Having a hereditary tendency or high probability for developing Type 2 diabetes. Lifestyle and weight are leading indicators.
How to find out what you have:
Screening for pre-diabetes and diabetes involves two key tests. Here are the blood sugar level numbers doctors look for:
A fasting blood sugar test involves a blood test following fasting overnight.
Normal: Below 100
Pre-diabetes: 100 to 125
Diabetes: 125 or greater
Oral glucose tolerance tests also require an overnight fast. Blood sugar levels are measured when you drink of a sugary solution and again two hours later.
Normal: Less than 140
Pre-diabetes: 140 to 199
Diabetes: 200 or more
Sources: The American Heritage Medical Dictionary, the Centers for Disease Control and Prevention and the Mayo Clinic