How Do I Know if I Have Diabetes?

What is diabetes?

Diabetes is a disease that occurs when your body doesn't make enough of a hormone called insulin, or if your body doesn't use insulin the right way. If left untreated, it may result in blindness, heart attacks, strokes, kidney failure and amputations. Only half of the people who have diabetes have been diagnosed, because in the early stages of diabetes there are few symptoms, or the symptoms may be the same as symptoms of other health conditions.

What are the symptoms of diabetes?

Early symptoms of diabetes may include the following:

  • Extreme thirst
  • Extreme hunger
  • Frequent urination
  • Sores or bruises that heal slowly
  • Dry, itchy skin
  • Unexplained weight loss
  • Blurry vision that changes from day to day
  • Unusual tiredness or drowsiness
  • Tingling or numbness in the hands or feet
  • Frequent or recurring skin, gum, bladder or vaginal yeast infections

If you are regularly experiencing 1 or more of these symptoms, call your family doctor right away.

Who is at risk for diabetes?

The early stages of diabetes have very few symptoms, so you may not know you have the disease. But damage may already be happening to your eyes, your kidneys and your cardiovascular system even before you notice symptoms. You are at risk for having diabetes if:

  • You're older than 45 years of age
  • You're overweight
  • You don't exercise regularly
  • Your parent, brother or sister has diabetes
  • You gave birth to a baby that weighed more than 9 pounds or you had gestational diabetes while you were pregnant
  • You're African American, Hispanic American/Latino, Native American, Asian American or Pacific Islander

If you have 1 or more of these risk factors, your doctor may want you to be tested for diabetes. You might also be tested at a younger age and more often if you have risk factors. Talk to your doctor about your risk of developing diabetes and about a plan for regular testing.

How will I be tested for diabetes?

Testing (also called "screening") is usually done with a fasting blood test. You'll be tested in the morning, so you shouldn't eat anything after dinner the night before. A normal blood sugar test result is below 110 mg per dL. A test result higher than 125 mg per dL suggests diabetes. However, you should have 2 tests that are higher than 125 mg per dL, on 2 different days, before a diagnosis of diabetes is made. Test results from 110 mg per dL to 125 mg per dL suggest that you have a higher risk of diabetes.

Why is it important for diabetes to be diagnosed early?

Many people have diabetes for about 5 years before they show symptoms . By that time, some people already have eye, kidney, gum or nerve damage caused by diabetes. There's no cure for diabetes, but there are ways for you to stay healthy and reduce the risk of complications. If you exercise, watch your diet, control your weight and take the medicine your doctor may prescribe, you can make a big difference in reducing or preventing the damage that diabetes can do. The earlier you know you have diabetes, the sooner you can make these important lifestyle changes.

Where can I get more information about diabetes?

Your family doctor can tell you how often you should be screened for diabetes. He or she can give you advice about diet and exercise, and tell you if you have the disease.

More Information

For more information talk to your doctor.

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Written by editorial staff.

Diagnosis and Classification of Diabetes Mellitus: New Criteria by Jennifer Mayfield, M.D., M.P.H (American Family Physician October 8, 1998,

Reviewed/Updated: 11/06
Created: 09/00