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Diabetes Health Center

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Diagnosing Diabetes

Diagnosing Diabetes

A doctor can diagnose diabetes by checking for symptoms such as excessive thirst and frequent urination and by testing for glucose in blood or urine. When blood glucose rises above a certain point, the kidneys pass the extra glucose in the urine. However, a urine test alone is not sufficient to diagnose diabetes.

A second method for testing glucose is a blood test usually done in the morning before breakfast (fasting glucose test) or after a meal (postprandial glucose test).

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The oral glucose tolerance test is a second type of blood test used to check for diabetes. Sometimes it can detect diabetes when a simple blood test does not. In this test, blood glucose is measured before and after a person has consumed a thick, sweet drink of glucose and other sugars. Normally, the glucose in a person's blood rises quickly after the drink and then falls gradually again as insulin signals the body to metabolize the glucose. In someone with diabetes, blood glucose rises and remains high after consumption of the liquid.

A doctor can decide, based on these tests and a physical exam, whether someone has diabetes. If a blood test is borderline abnormal, the doctor may want to monitor the person's blood glucose regularly. If a person is overweight, he or she probably will be advised to lose weight. The doctor also may monitor the patient's heart, since diabetes increases the risk of heart disease.

Points to Remember

A doctor will diagnose diabetes by looking for four kinds of evidence:

  • risk factors like exercise weight and a family history of diabetes
  • symptoms such as thirst and frequent urination
  • complications like heart trouble
  • signs of excess glucose or sugar in blood and urine tests.

Treating Diabetes

The goals of diabetes treatment are to keep blood glucose within normal range and to prevent long-term complications. Why control blood glucose? In the first place, diabetes can cause short-term effects: some are unpleasant and some are dangerous. These include thirst, frequent urination, weakness, lack of ability to concentrate, loss of coordination, and blurred vision. Loss of consciousness is possible with very high or low blood sugar levels, but is more of a danger in insulin-dependent than in noninsulin-dependent diabetes.

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