Type 2 Diabetes
Type 2 diabetes is a lifelong (chronic) disease in which there is a high level of sugar (glucose) in the blood. Type 2 diabetes is the most common form of diabetes.
Noninsulin-dependent diabetes; Diabetes - type 2; Adult-onset diabetes
Insulin is a hormone produced in the pancreas by special cells, called beta cells. The pancreas is behind the stomach. Insulin is needed to move blood sugar (glucose) into cells. There, it is stored and later used for energy.
When you have type 2 diabetes, your fat, liver, and muscle cells do not respond correctly to insulin. This is called insulin resistance. As a result, blood sugar does not get into these cells to be stored for energy.
When sugar cannot enter cells, a high level of sugar builds up in the blood. This is called hyperglycemia.
Type 2 diabetes usually occurs slowly over time. Most people with the disease are overweight when they are diagnosed. Increased fat makes it harder for your body to use insulin the correct way.
Type 2 diabetes can also develop in people who are thin. This is more common in the elderly.
Family history and genes play a role in type 2 diabetes. Low activity level, poor diet, and excess body weight around the waist increase your chance of getting the disease.
People with type 2 diabetes often have no symptoms at first. They may not have symptoms for many years.
Early symptoms of diabetes may include:
- Bladder, kidney, skin, or other infections that are more frequent or heal slowly
- Increased thirst
- Increased urination
The first symptom may also be:
Exams and Tests
Your doctor may suspect that you have diabetes if your blood sugar level is higher than 200 mg/dL. To confirm the diagnosis, one or more of the following tests must be done.
Diabetes blood tests:
- Fasting blood glucose level. Diabetes is diagnosed if it is higher than 126 mg/dL two times.
- Hemoglobin A1c test. Diabetes is diagnosed if the test result is 6.5% or higher.
- Oral glucose tolerance test. Diabetes is diagnosed if the glucose level is higher than 200 mg/dL 2 hours after drinking a special sugar drink.
Diabetes screening is recommended for:
- Overweight children who have other risk factors for diabetes, starting at age 10 and repeated every 2 years
- Overweight adults (BMI greater than 25) who have other risk factors
- Adults over age 45 every 3 years
If you have been diagnosed with type 2 diabetes, you need to work closely with your doctor. You will likely need to see your doctor every 3 months. At these visits, you can expect your doctor to:
- Check your blood pressure
- Check the skin and bones on your feet and legs
- Check if your feet are becoming numb
- Examine the back part of the eye with a special lighted instrument
The following tests will help you and your doctor monitor your diabetes and prevent problems.
- Have your blood pressure checked at least every year (blood pressure goals should be 140/80 mm Hg or lower).
- Have your A1c test (hemoglobin A1c) every 6 months if your diabetes is well controlled. Have the test every 3 months if your diabetes is not well controlled.
- Have your cholesterol and triglyceride levels checked yearly.
- 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.
The goal of treatment at first is to lower your high blood glucose levels. Long-term goals are to prevent problems from diabetes.
The most important way to treat and manage type 2 diabetes is activity and nutrition.
Learn These Skills
Learning diabetes management skills will help you live well with diabetes. These skills help prevent health problems and the need for medical care. Skills include:
- How to test and record your blood glucose
- What to eat and when
- How to take medications, if needed
- How to recognize and treat low and high blood sugar
- How to handle sick days
- Where to buy diabetes supplies and how to store them
It may take several months to learn these skills. Keep learning about diabetes, its complications, and how to control and live with the disease. Stay up-to-date on new research and treatments.
Managing Your Blood Sugar
Checking your blood sugar levels yourself and writing down the results tells you how well you are managing your diabetes. Talk to your doctor and diabetes educator about how often to check.
To check your blood sugar level, you use a device called a glucose meter. Usually, you prick your finger with a small needle called a lancet. This gives you a tiny drop of blood. You place the blood on a test strip and put the strip into the meter. The meter gives you a reading that tells you the level of your blood sugar.
Your doctor or diabetes educator will help set up a testing schedule for you. Your doctor will help you set a target range for your blood sugar numbers. Keep these factors in mind:
- Most people with type 2 diabetes only need to check their blood sugar once or twice a day.
- If your blood sugar level is under control, you may only need to check it a few times a week.
- You may test yourself when you wake up, before meals, and at bedtime.
- You may need to test more often when you are sick or under stress.
Keep a record of your blood sugar for yourself and your doctor. Based on your numbers, changes may need to be made to your meals, activity or medicines to keep your blood sugar level in the right range.
Diet and Weight Control
Work closely with your doctor, nurse, and dietitian to learn how much fat, protein, and carbohydrates you need in your diet. Your meal plans should fit your lifestyle and habits and should include foods that you like.
Managing your weight and having a well-balanced diet are important. Some people with type 2 diabetes can stop taking medicines after losing weight. This does not mean that their diabetes is cured. They still have diabetes.
Very obese patients whose diabetes is not well managed with diet and medicine may consider weight loss (bariatric) surgery.
Regular Physical Activity
Regular activity is important for everyone. It is even more important when you have diabetes. Reasons why exercise is good for your health:
- Lowers your blood sugar level without medicine
- Burns extra calories and fat to help manage your weight
- Improves blood flow and blood pressure
- Increases your energy level
- Improves your ability to handle stress
Talk to your doctor before starting any exercise program. People with type 2 diabetes may need to take special steps before, during, and after physical activity or exercise.
Medications to Treat Diabetes
If diet and exercise do not help keep your blood sugar at normal or near-normal levels, your doctor may prescribe medication. Since these drugs help lower your blood sugar levels in different ways, your doctor may have you take more than one drug.
Some of the most common types of medication are listed below. They are taken by mouth or injection.
- Alpha-glucosidase inhibitors
- DPP IV inhibitors
- Injectable medicines
You may need to take insulin if your blood sugar cannot be controlled with any of the above medicines. Insulin must be injected under the skin using a syringe, insulin pen, or pump. It cannot be taken by mouth because the acid in the stomach destroys insulin.
Your doctor may prescribe medicines or other treatments to reduce your chance of developing some of the more common complications of diabetes, including:
- Eye disease
- Kidney disease
- Heart disease and stroke
People with diabetes are more likely than those without diabetes to have foot problems. Diabetes damages the nerves. This can make you less able to feel pressure on the foot. You many not notice a foot injury until you get a severe infection.
Diabetes can also damage blood vessels. Small sores or breaks in the skin may become deeper skin sores (ulcers). The affected limb may need to be amputated if these skin ulcers do not heal or become larger, deeper or infected.
To prevent problems with your feet:
- Stop smoking if you smoke.
- Improve control of your blood sugar.
- Get a foot exam by your doctor at least twice a year and learn if you have nerve damage.
- Check and care for your feet every day. This is very important when you already have nerve or blood vessel damage or foot problems.
- Make sure you wear the right kind of shoes. Ask your doctor what is right for you.
There are many diabetes resources that can help you understand more about type 2 diabetes. You can also learn ways to manage your condition so you can live well with diabetes.
Diabetes is a lifelong disease and there is no cure.
Some people with type 2 diabetes no longer need medicine if they lose weight and become more active. When they reach their ideal weight, their body's own insulin and a healthy diet can control their blood sugar level.
After many years, diabetes can lead to serious problems:
- You could have eye problems, including trouble seeing (especially at night), and light sensitivity. You could become blind.
- Your feet and skin can develop sores and infections. After a long time, your foot or leg may need to be amputated. Infection can also cause pain and itching in other parts of the body.
- Diabetes may make it harder to control your blood pressure and cholesterol. This can lead to a heart attack, stroke, and other problems. It can become harder for blood to flow to your legs and feet.
- Nerves in your body can get damaged, causing pain, tingling, and numbness.
- 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 make it harder for men to have an erection.
- High blood sugar and other problems can lead to kidney damage. Your kidneys may not work as well as they used to. They may even stop working so that you need dialysis or a kidney transplant.
When to Contact a Medical Professional
Call 911 right away if you have:
- Chest pain or pressure
- Fainting or unconsciousness
- Shortness of breath
These symptoms can quickly get worse and become emergency conditions (such as convulsions or hypoglycemic coma).
Also call your doctor if you have:
- Numbness, tingling, or pain in your feet or legs
- Problems with your eyesight
- Sores or infections on your feet
- Symptoms of high blood sugar (being very thirsty, having blurry vision, having dry skin, feeling weak or tired, needing to urinate a lot)
- Symptoms of low blood sugar (feeling weak or tired, trembling, sweating, feeling irritable, having trouble thinking clearly, fast heartbeat, double or blurry vision, feeling uneasy)
You can help prevent type 2 diabetes by keeping a healthy body weight and an active lifestyle.
American Diabetes Association. Standards of medical care in diabetes -- 2014. Diabetes Care. 2014;37 Suppl 1:S14-S80.
Stone NJ, Robinson JG, Lichtenstein AH, Goff DC Jr, Lloyd-Jones DM, Smith SC Jr, et al. Treatment of blood cholesterol to reduce atherosclerotic cardiovascular disease risk in adults: synopsis of the 2013 American College of Cardiology/American Heart Association cholesterol guideline. Ann Intern Med. 2014 Mar 4;160(5):339-43.
Eisenbarth GS, Polonsky KS, Buse JB. Type 2 diabetes mellitus. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology. 12th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 31.
Inzucchi SE, Sherwin RS. Type 2 diabetes mellitus. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 237.
Pories WJ, Mehaffy JH, Staton KM. The surgical treatment of type two diabetes mellitus. Surg Clin North Am. 2011;91:821-836.
Reviewed By: Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team. Editorial update: 05/14/14