Overview of Diabetes

An estimated 26 million Americans have diabetes, a disease in which there is too much sugar in the bloodstream. About 7 million of them, however, have not yet been diagnosed with the disease.

Diabetes occurs when the pancreas, a gland behind the stomach, does not produce enough of the hormone insulin, or the body can’t use insulin properly. Insulin helps carry sugar from the bloodstream into the cells. Once inside the cells, sugar is converted into energy for immediate use or stored for the future. That energy fuels many of our bodily functions.

There are two types of diabetes: type 1 and type 2.

Type 1 diabetes occurs when the pancreas makes very little or no insulin.. People with type 1 diabetes must take insulin every day to replace the insulin their bodies are not making. This form of the disease is most often seen in children. It used to be called or juvenile diabetes, but it can occur at any age.

Type 2 diabetes is the most common form of the disease, affecting 90 to 95 percent of people with diabetes. In type 2 diabetes, the body is resistant to the action of insulin, meaning it cannot use insulin properly, so it cannot carry sugar into the cells. Although the body makes some insulin, it is not enough to overcome this resistance. You are more likely to develop diabetes if you are overweight, have a family history of diabetes, or have a history of diabetes during pregnancy. Other groups more likely to have the disease are people over age 45 and non-Caucasians. A simple blood test can tell you if you have diabetes.

Diabetes During Pregnancy

A temporary form of diabetes can occur when a woman is pregnant. This is called gestational diabetes and often has no symptoms. Most women are tested for blood sugar problems at some point in their pregnancy. If a woman has high blood sugar, she will have to follow a special diet for the rest of the pregnancy. In some cases, she may also need to take insulin. About 3 to 5 percent of pregnant women develop gestational diabetes.

Gestational diabetes occurs more often in African Americans, Native Americans, Hispanic Americans, Asian Americans, in women with a family history of diabetes, and in those who are overweight. Although this form of diabetes usually disappears after the baby is born, more than half of women with gestational diabetes develop type 2 diabetes later in life.


Guillermo Umpierrez, MD
Emory University School of Medicine

Margaret Eckert-Norton, PhD
SUNY Downstate

Last Updated: May 2013