Diabetes also known medically as diabetes mellitus is a group of diseases that affect the way your body uses blood sugar (glucose). This sugar is vital to your health because it's your body's main source of fuel.

Normally, glucose is able to enter your cells because of the action of insulin a hormone secreted by your pancreas. Insulin acts like a key to unlock microscopic doors that allow glucose into your cells. But in diabetes mellitus, this process goes awry. Instead of being transported into your cells, glucose accumulates in your bloodstream and eventually is excreted in your urine. This usually occurs either because your body doesn't produce enough insulin or because the cells don't respond to insulin properly.

Diabetes mainly occurs in two forms:

  • Type 1 diabetes. This type develops when your pancreas makes little or no insulin. It affects between 5 percent and 10 percent of people with the disease.
  • Type 2 diabetes. This type is far more common than type 1, affecting between 90 percent and 95 percent of people with diabetes over age 20. It occurs when your body is resistant to the effects of insulin or your pancreas produces some, but not enough, insulin to maintain a normal glucose level.

More Americans have diabetes than ever before. The disease affects 17 million adults and children, yet close to a third of them may not know they have it. That's because diabetes can develop gradually over many years, often with no symptoms. Both types of diabetes are serious. The accumulation of glucose in your blood can damage almost every major organ in your body. Eventually, diabetes can be fatal. It's the sixth leading cause of death in the United States.

No one has yet found a cure for diabetes mellitus. But the good news is that eating right, maintaining a healthy weight and getting plenty of exercise can help prevent the disease. And if you have diabetes, diet and exercise along with medications that control blood sugar can help you continue to live a healthy and active life.