Diabetes is a lifelong
(chronic) disease in which there are high levels of sugar in the
Causes, incidence, and risk factors
Insulin is a hormone produced by the pancreas to control blood
sugar. Diabetes can be caused by too little insulin, resistance to
insulin, or both.
To understand diabetes, it is important to first understand the
normal process by which food is broken down and used by the body for
energy. Several things happen when food is digested:
• A sugar called glucose enters the bloodstream. Glucose is a source of
fuel for the body.
• An organ called the pancreas makes insulin. The role of insulin is to
move glucose from the bloodstream into muscle, fat, and liver cells,
where it can be used as fuel.
People with diabetes have high blood sugar because their body cannot
move sugar into fat, liver, and muscle cells to be stored for
energy. This is because either:
• Their pancreas
does not make enough insulin
• Their cells do not respond to insulin normally
• Both of the above
There are three major types of diabetes. The causes and risk factors
are different for each type:
• Type 1 diabetes can occur at any age, but it is most often diagnosed in
children, teens, or young adults. In this disease, the body makes
little or no insulin. Daily injections of insulin are needed. The
exact cause is unknown.
• Type 2 diabetes makes up most of diabetes cases. It most often occurs in
adulthood, but teens and young adults are now being diagnosed with
it because of high obesity rates. Many people with type 2 diabetes
do not know they have it.
• Gestational diabetes is high blood sugar that develops at any time
during pregnancy in a woman who does not have diabetes.
Diabetes affects more than 20 million Americans. Over 40 million
Americans have pre-diabetes (early type 2 diabetes).
High blood sugar levels can cause several symptoms, including:
• Blurry vision
• Excess thirst
• Frequent urination
• Weight loss
Because type 2 diabetes develops slowly, some people with high blood
sugar have no symptoms.
Symptoms of type 1 diabetes develop over a short period of time.
People may be very sick by the time they are diagnosed.
Signs and Tests
A urine analysis may be used to look for high blood sugar. However,
a urine test alone does not diagnose diabetes.
Your health care provider may suspect that you have diabetes if your
blood sugar level is higher than 200 mg/dL. To confirm the
diagnosis, one or more of the following tests must be done.
• Fasting blood glucose level -- diabetes is diagnosed if it is higher
than 126 mg/dL twice. Levels between 100 and 126 mg/dL are called
impaired fasting glucose or pre-diabetes. These levels are risk
factors for type 2 diabetes.
• Hemoglobin A1c test --
• Normal: Less than 5.7%
• Pre-diabetes: 5.7% - 6.4%
• Diabetes: 6.5% or higher
• Oral glucose tolerance test -- diabetes is diagnosed if glucose level
is higher than 200 mg/dL after 2 hours. (This test is used more
often for type 2 diabetes.)
Screening for type 2 diabetes in people who have no symptoms is
children who have other risk factors for diabetes, starting at age
10 and repeated every 2 years
• Overweight adults (BMI greater than 25) who have other risk factors
• Adults over age 45, repeated every 3 years
There is no cure for diabetes. Treatment involves medicines, diet,
and exercise to control blood sugar and prevent symptoms and