Diabetes is a chronic disease in which blood sugar levels are above normal.

People with diabetes have problems converting food to energy.

After a meal, food is broken down into a sugar called blood glucose, which is carried by the blood to cells throughout the body. Insulin, a hormone made in the pancreas, allows blood glucose to enter the cells of the body where it is used for energy. People develop diabetes because the pancreas produces little or no insulin or because the cells of the body do not use insulin properly. As a result, the sugar builds up in the blood and is transported to the kidney, where it is eliminated from the body in the urine. Thus, the body loses its main source of fuel even though the blood contains large amounts of blood glucose.

When insulin is no longer made, it must be obtained from another source—insulin injections or an insulin pump. When the body does not use insulin properly, people with diabetes may take insulin or other blood glucose-lowering medications. Neither insulin nor other medications, however, are cures for diabetes; they only help to manage the disease.

Taking care of diabetes is important. Over the years, ongoing high blood glucose, also called hyperglycemia, can lead to serious health problems. On the other hand, low blood glucose can be very dangerous and cause life-threatening complications. See signs and symptoms of both below.

Poorly controlled diabetes increases a person’s risk for heart disease and stroke. Some of these problems can occur in teens and young adults who develop diabetes during childhood. The good news is that research shows these problems can be greatly reduced, delayed, or possibly prevented through intensive treatment that keeps blood glucose levels near normal.