Diabetes is a condition where people don't produce enough insulin, and/or their cells don't respond properly to insulin. Insulin is an important hormone produced by the pancreas that moves glucose, a type of sugar, into the body's cells from the blood. Once inside the body's cells, glucose is used as a source of energy. If insulin isn't available or doesn't work correctly to move glucose from the blood into cells, glucose will stay in the blood. Blood sugar levels will then increase.
In the United States, almost 26 million people have diabetes, and over one-third of those with the condition are unaware they have it.
There are two main kinds of diabetes: type 1 diabetes and type 2 diabetes.
Type 1 diabetes used to be called "juvenile" or "insulin dependent"
diabetes. It usually occurs in childhood or adolescence. Everyone with type
1 diabetes requires regular insulin injections. Less than 10% of all people
with diabetes have type 1.
Type 2 diabetes used to be called "adult-onset" or "non-insulin
independent" diabetes. It usually occurs in people over 40 years of age but can occur in younger adults and in children.
People with type 2 diabetes usually have a family history of the condition and
are most often overweight. Although most people with type 2 diabetes do not
require insulin, some people need insulin injections to control their blood
glucose. More than 90% of all people with diabetes have type 2.
Some people with type 2 diabetes develop a condition called impaired glucose
tolerance (IGT) before being diagnosed with diabetes. IGT means that the body
has become less sensitive to the effects of insulin, and has to work harder
to control blood glucose levels. A person with IGT has blood sugar (glucose)
levels that are higher than normal but not high enough to say they have diabetes.
As in type 2 diabetes, the body produces insulin, but there may be less of it,
or it may not work properly.
Studies have shown that keeping blood sugar as close to the normal range as
possible can help prevent the long-term health problems associated with diabetes,
such as coronary artery (heart) disease, kidney disease, and blindness. Whichever
type of diabetes you have, you'll need to measure your blood sugar frequently
and follow a treatment plan to keep your blood sugar under control. Your doctor
and pharmacist can show you how to monitor blood sugar levels. See our disease
database articles on diabetes for more information.