Diabetes

Symptoms

High blood levels of glucose can cause several problems, including frequent urination, excessive thirst, hunger, fatigue, weight loss, and blurry vision. However, because type 2 diabetes develops slowly, some people with high blood sugar experience no symptoms at all.

Symptoms of type 1 diabetes:

• Increased thirst
• Increased urination
• Weight loss in spite of increased appetite
• Fatigue
• Nausea
• Vomiting

Patients with type 1 diabetes usually develop symptoms over a short period of time, and the condition is often diagnosed in an emergency setting.

Symptoms of type 2 diabetes:

• Increased thirst
• Increased urination
• Increased appetite
• Fatigue
• Blurred vision
• Slow-healing infections
• Impotence in men

Exams and Tests

A urine analysis may be used to look for glucose and ketones from the breakdown of fat. However, a urine test alone does not diagnose diabetes. The following blood glucose tests are used to diagnose diabetes:

• Fasting blood glucose level -- diabetes is diagnosed if higher than 126 mg/dL on two occasions. Levels between 100 and 126 mg/dl are referred to as impaired fasting glucose or pre-diabetes. These levels are considered to be risk factors for type 2 diabetes and its complications.
• Random (non-fasting) blood glucose level -- diabetes is suspected if higher than 200 mg/dL and accompanied by the classic symptoms of increased thirst, urination, and fatigue. (This test must be confirmed with a fasting blood glucose test.)
• Oral glucose tolerance test -- diabetes is diagnosed if glucose level is higher than 200 mg/dL after 2 hours (This test is used more for type 2 diabetes.)

You should also ask your doctor how often to you need your hemoglobin A1c (HbA1c) level checked. The HbA1c is a measure of average blood glucose during the previous 2 to 3 months. It is a very helpful way to determine how well treatment is working.

Ketone testing is another test that is used in type 1 diabetes. Ketones are produced by the breakdown of fat and muscle, and they are harmful at high levels. The ketone test is done using a urine sample. High levels of blood ketones may result in a serious condition called ketoacidosis. Ketone testing is usually done at the following times:

• When the blood sugar is higher than 240 mg/dL
• During acute illness (for example, pneumonia, heart attack, or stroke)
• When nausea or vomiting occur
• During pregnancy

References

Standards of medical care in diabetes--2007. Diabetes Care. Jan 2007;30 Suppl 1:S4-S41.

Larsen PR, Kronberg HM, Schlomo M, et al. Williams Textbook of Endocrinology. 10th ed. St. Louis, Mo: WB Saunders; 2003:1427-1468, 1485-1504.

Armstrong C. ADA Releases Standards of Medical Care for Patients with Diabetes. Am Fam Physician. Sept 2006; 74(5); 871-874.

Caballero E. Prediabetes. J Clin Endocrinol Metab. Jan 2007; 92(1); 15A-16A.