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Basics of Type 1 Diabetes

What you need to know about type 1 diabetes.

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Diabetes is a condition in which a person’s blood sugar is above normal.

For most of us, the food we eat gets turned into glucose, or sugar. The pancreas produces insulin, which helps glucose get into cells. This process creates the energy that fuels our body. With type 1 diabetes, the body doesn’t make insulin at all, or doesn’t make enough of it. Without treatment, blood sugar levels become too high.


Autoimmune, genetic and environmental factors, and possibly viruses, may be risk factors for developing type 1 diabetes. Only about 5 percent of people with diabetes have type 1. Type 1 diabetes is most common in children, though adults can develop it, too.

Common symptoms

Some people do not show symptoms of diabetes. But some of the more common symptoms may include:

  • Frequent urination
  • Extreme thirst or hunger
  • Unexplained weight loss
  • Fatigue
  • Irritability
  • Vision changes


Type 1 diabetes is diagnosed with blood tests that measure how much sugar is in the blood. If a first test is positive, the test may be repeated before a diagnosis is made. The common blood tests to diagnose diabetes are:

  • Fasting plasma glucose test. This test requires the person to not eat or drink for at least eight hours before the test. A level of 126 mg/dl or higher can indicate diabetes.
  • Oral glucose tolerance test. This requires fasting for at least eight hours before the test. Then, two hours before the test, the person drinks a special sugary beverage. Your blood sugar levels will be compared to what is expected as a normal range.  Abnormal levels may point to diabetes.
  • Hemoglobin A1C test. This test looks at an average of blood sugar for the past two to three months. Fasting is not required. An A1C of 6.5 percent or higher is typical in people with diabetes. This test is also used to measure how well blood sugar has been controlled over the previous three months.
  • Random plasma glucose test. There are no fasting or drinking requirements. A level of 200 mg/dL or higher may mean diabetes. However, this test is not routinely used to diagnose diabetes.

Managing diabetes

Blood sugar: A big part of living with type 1 diabetes means managing blood sugar levels.

People with type 1 diabetes may take insulin several times a day to help maintain a steady blood sugar level. Insulin can be taken with an insulin pen or through an injection or pump.

Keeping a close eye on your blood sugar levels is especially important to help prevent the levels from becoming too high or too low. That said, it’s also important for you to know what to do if you develop complications or if you are managing other health conditions, such as heart disease. Be sure to speak with your doctor about what to be aware of and what do in these situations.

Diet: This is also important in the management of your diabetes. Consult your doctor about the optimal diet for you. In general, a diet of fruits and vegetables, whole grains, lean protein and nonfat dairy is recommended. Try to limit your consumption of foods with added fats, sugars or sodium. Also limit how many sugary beverages you drink. A dietitian may help you develop an eating plan that’s right for you.

Drinking alcohol may put people with diabetes — especially those who take insulin — at greater risk for delayed low blood sugar. Talk with your doctor about whether or not it is safe for you to drink. If it is safe for you to drink and you choose to do so, be aware of how alcohol may affect your blood sugar levels. Talk to your doctor about this possible complication. And remember, if you choose to drink, drink in moderation, which means one drink a day for women, two drinks a day for men.

Exercise: This may help keep blood sugar levels stable. Adults with diabetes should aim for at least 150 minutes a week of moderate-intensity aerobic activity. Try to spread the activity over at least three days, and don’t skip activity more than two days in a row.

Everyone, including people who have diabetes, should limit sedentary time to no more than 90 minutes at a time. Strength training at least two days a week is also an important part of a healthy exercise program, as long as you do not have certain conditions that can increase your risk for complications. Be sure to check with your doctor before starting or increasing your exercise. He or she can tell you what activities are appropriate for you and which ones you should avoid.

Don't smoke. If you do, quit.

A health care team is important in helping manage diabetes, too. That team typically is made up of a doctor who specializes in diabetes care, nurse, eye doctor and dietitian (or certified diabetes educator) who work with you to help monitor blood sugar levels. You may also have a mental health professional, pharmacist, dentist and a foot doctor on your team. The support of others who are also dealing with type 1 diabetes can also be helpful. Check for local support groups.

By Susan G. Warner, Contributing Writer

American Diabetes Association. Standards of medical care in diabetes—2015. Accessed: October 2, 2015.
Centers for Disease Control and Prevention. Basics about diabetes. Accessed: October 2, 2015.
American Diabetes Association. Living with type 1 diabetes. Accessed: October 2, 2015.
National Diabetes Information Clearinghouse. What are the signs and symptoms of diabetes? Accessed: October 2, 2015.

Last Updated: October 15, 2015