Type 1 diabetes is a lifelong (chronic) disease in which there are high levels of sugar (glucose) in the blood.

Insulin-dependent diabetes; Juvenile onset diabetes; Diabetes - type 1

These symptoms may be the first signs of type 1 diabetes, or may occur when the blood sugar is high:

• Being very thirsty
• Feeling hungry
• Feeling tired or fatigued
• Having blurry eyesight
• Losing the feeling or feeling tingling in your feet
• Losing weight without trying
• Urinating more often

For other people, these warning symptoms may be the first signs of type 1 diabetes, or they may happen when the blood sugar is very high (see: diabetic ketoacidosis):

• Deep, rapid breathing
• Dry skin and mouth
• Flushed face
• Fruity breath odor
• Nausea or vomiting, inability to keep down fluids
• Stomach pain

Low blood sugar (hypoglycemia) can develop quickly in people with diabetes who are taking insulin. Symptoms usually appear when the blood sugar level falls below 70 mg/dL. Watch for:

• Headache
• Hunger
• Nervousness
• Rapid heartbeat (palpitations)
• Shaking
• Sweating
• Weakness

Diabetes is diagnosed with the following blood tests:

• Fasting blood glucose level -- diabetes is diagnosed if it is higher than 126 mg/dL two times
• Random (nonfasting) blood glucose level -- you may have diabetes if it is higher than 200 mg/dL, and you have symptoms such as increased thirst, urination, and fatigue (this must be confirmed with a fasting test)
• Oral glucose tolerance test -- diabetes is diagnosed if the glucose level is higher than 200 mg/dL after 2 hours
• Hemoglobin A1c test
  • Normal: Less than 5.7%
  • Pre-diabetes: Between 5.7% and 6.4%
  • Diabetes: 6.5% or higher

Ketone testing is also sometimes used. The ketone test is done using a urine sample or blood sample. Ketone testing may be done:

• When the blood sugar is higher than 240 mg/dL
• During an illness such as pneumonia, heart attack, or stroke
• When nausea or vomiting occur
• During pregnancy

The following tests or exams will help you and your doctor monitor your diabetes and prevent problems caused by diabetes:

• Check the skin and bones on your feet and legs.
• Check to see if your feet are getting numb.
• Have your blood pressure checked at least every year (blood pressure goal should be 130/80 mm/Hg or lower).
• Have your hemoglobin A1c test (HbA1c) done every 6 months if your diabetes is well controlled; otherwise, every 3 months.
• Have your cholesterol and triglyceride levels checked yearly (aim for LDL cholesterol levels below 70-100 mg/dL).
• Get yearly tests to make sure your kidneys are working well (microalbuminuria and serum creatinine).
• Visit your eye doctor at least once a year, or more often if you have signs of diabetic eye disease.
• See the dentist every 6 months for a thorough dental cleaning and exam. Make sure your dentist and hygienist know that you have diabetes.

For more information and resources, see diabetes support group.

Diabetes is a lifelong disease and there is not yet a cure. However, the outcome for people with diabetes varies.

Studies show that tight control of blood glucose can prevent or delay problems with the eyes, kidneys, nervous system, and heart in type 1 diabetes. However, problems may occur even in people with good diabetes control.

If you have diabetes, your risk of a heart attack is the same as someone who has already had a heart attack. Both women and men with diabetes are at risk. You may not even have the normal signs of a heart attack.

After many years, diabetes can lead to other serious problems:

• You could have eye problems, including trouble seeing (especially at night) and sensitivity to light. You could become blind.
• Your feet and skin could develop sores and infections. If you have these sores for too long, your foot or leg may need to be removed. Infection can also cause pain and itching.
• Diabetes may make it harder to control your blood pressure and cholesterol. This can lead to heart attack, stroke, and other problems. It can become harder for blood to flow to the legs and feet.
• Nerves in the body can become damaged, causing pain, tingling, and loss of feeling.
• Because of nerve damage, you could have problems digesting the food you eat. You could feel weakness or have trouble going to the bathroom. Nerve damage can also make it harder for men to have an erection.
• High blood sugar and other problems can lead to kidney damage. The kidneys might not work as wellas they used to. They may even stop working.

Call 911 if you have:

• Chest pain or pressure, shortness of breath, or other signs of angina
• Loss of consciousness
• Seizures

Call your health care provider or go to the emergency room if you have symptoms of diabetic ketoacidosis.

Also call your doctor if you have:

• Blood sugar levels that are higher than the goals you and your doctor have set
• Numbness, tingling, or pain in your feet or legs
• Problems with your eyesight
• Sores or infections on your feet
• Symptoms that your blood sugar is getting too low (feeling weak or tired, trembling, sweating, feeling irritable, having trouble thinking clearly, fast heartbeat, double or blurry vision, feeling uneasy)
• Symptoms that your blood sugar is too high (being very thirsty, having blurry vision, having dry skin, feeling weak or tired, needing to urinate a lot)
• You are having blood sugar readings below 70 mg/dL

You can treat early signs of hypoglycemia at home by eating sugar or candy, or by taking glucose tablets. If your signs of hypoglycemia continue or your blood glucose levels stay below 60 mg/dL, go to the emergency room.

There is no way to prevent type 1 diabetes. There is no screening test for type 1 diabetes in people who have no symptoms.

Stay up-to-date with all of your vaccinations and get a flu shot every year in the fall.

Alemzadeh R, Ali O. Diabetes Mellitus. In: Kliegman RM, ed. Kliegman: Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa: Saunders; 2011:chap 583.

American Diabetes Association. Standards of medical care in diabetes -- 2011. Diabetes Care. 2011. 34 Suppl 1:S11-S61.

Eisenbarth GS, Polonsky KS, Buse JB. Type 1 diabetes mellitus. In: Kronenberg HM, Melmed S, Polonsky KS, Larsen PR. Kronenberg: Williams Textbook of Endocrinology. 11th ed. Philadelphia, Pa: Saunders Elsevier;2008:chap 31.

Pignone M, Alberts MJ, Colwell JA, Cushman M, Inzucchi SE, Mukherjee D, et al. Aspirin for primary prevention of cardiovascular events in people with diabetes: a position statement of the American Diabetes Association, and an expert consensus document of the American College of Cardiology Foundation. Circulation. 2010. 121:2694-2701.