Type 1 Diabetes Mellitus, Diagnosis, Adult

Type 1 diabetes mellitus, or type 1 diabetes, is a long-term (chronic) disease. It happens when the cells in the pancreas that make a hormone called insulin are destroyed.

Normally, insulin lets blood sugar (glucose) enter cells in your body. This gives you energy. If you have type 1 diabetes, glucose cannot get into cells. It builds up in the blood instead. This causes high blood glucose (hyperglycemia).

There is no cure for type 1 diabetes. Treatment can help you manage your condition.

What are the causes?

The exact cause of type 1 diabetes is not known.

What increases the risk?

• You have a gene for type 1 diabetes that was passed down to you from a parent (inherited).
• You have an autoimmune disorder. This means that your body's disease-fighting system (immune system) attacks your body.
• You have been exposed to certain viruses.
• You live in an area with cold weather.

What are the signs or symptoms?

• Increased thirst or hunger.
• Needing to pee (urinate) more often or peeing more at night.
• Sudden weight changes that you cannot explain.
• Tiredness (fatigue) or weakness.
• Vision changes. These may include blurry vision.

How is this diagnosed?

• A fasting blood glucose (FBG) test. You will not be allowed to eat (you will fast) for 8 hours or more before a blood sample is taken.
• A random blood glucose test. This test checks your blood glucose at any time of day no matter when you last ate.
• A hemoglobin A1C (A1C) blood test. This shows what your blood glucose levels have been over the last 2–3 months.

• Your FBG level is 126 mg/dL (7 mmol/L) or higher.
• Your random blood glucose level is 200 mg/dL (11.1 mmol/L) or higher.
• Your A1C level is 6.5% or higher.

These blood tests may be done more than once. You may also need other blood tests.

How is this treated?

• Take insulin every day. This helps to keep your blood glucose levels in the right range.
• Take medicines to help prevent problems from diabetes. You may need to take:
  • Aspirin.
  • Medicine to lower your cholesterol.
  • Medicine to control your blood pressure.
• Check your blood glucose as often as told.
• Make diet and lifestyle changes. You may be told to:
  • Follow a nutrition plan that has been made just for you by a dietitian.
  • Get regular exercise.
  • Find ways to manage stress.

• 80–130 mg/dL (4.4–7.2 mmol/L) before meals (preprandial).
• Below 180 mg/dL (10 mmol/L) after meals (postprandial).

Follow these instructions at home:

Questions to ask your health care provider

• Do I need to meet with a certified diabetes care and education specialist?
• Should I join a support group for people with diabetes?
• What equipment will I need to manage my diabetes at home?
• What diabetes medicines should I take, and when?
• How often should I check my blood glucose?
• What number should I call if I have questions?
• When is my next appointment?

General instructions

• Take over-the-counter and prescription medicines only as told by your provider.
• Keep all follow-up visits. You will need regular blood tests to make sure the treatments are working. Your provider may adjust your medicines based on your test results.

Where to find more information

• American Diabetes Association (ADA): diabetes.org
• Association of Diabetes Care and Education Specialists (ADCES): diabeteseducator.org
• International Diabetes Federation (IDF): idf.org

Contact a health care provider if:

• Your blood glucose level is higher than 240 mg/dL (13.3 mmol/L) for 2 days in a row.
• You have been sick or have had a fever for 2 days or more, and you are not getting better.
• For more than 6 hours, you:
  • Cannot eat or drink.
  • Have nausea and vomiting.
  • Have diarrhea.

Get help right away if:

• Your blood glucose is less than 54 mg/dL (3 mmol/L).
• You become confused, or you have trouble thinking clearly.
• You have trouble breathing.

• Do not wait to see if the symptoms will go away.
• Do not drive yourself to the hospital.