Complications of Type 2 Diabetes and Reducing Your Risk of Developing Complications
Possible ComplicationsWhen blood glucose (sugar) levels are out of the normal range, complications may develop. These include the following:
- In the short-term:
- In the long-term:
HypoglycemiaHypoglycemia is more common in people who take insulin to control their glucose levels. But it can also occur in people who take oral medication. Hypoglycemia can be caused by any of the following:
- Taking too much insulin or oral diabetes medication
- Skipping or delaying a meal, or eating a smaller meal than usual
- Exercising harder or longer than your usual pattern
- Lightheadedness or fainting
- Pale skin color
- Sudden moodiness or behavior change
- Clumsy or jerky movements
- Confusion or difficulty paying attention
- Tingling sensations around the mouth
- Loss of consciousness
- 4 ounces (118 milliliters) fruit juice or regular soda
- 2 tablespoons raisins
- 4 or 5 saltine crackers
- 4 teaspoons sugar
- 1 tablespoon honey or corn syrup
HyperglycemiaLong-term hyperglycemia is the major cause of many of the complications that occur in people with diabetes. Hyperglycemia occurs when you do not have enough insulin to remove the glucose in your blood, or when your body does not use insulin properly. It can be caused by:
- Taking too little insulin or oral medication
- Eating a larger meal than usual
- Experiencing stress from an illness or from factors in daily life
- Frequent urination
- Increased thirst
- Blurred vision
- Unexplained weight loss
Hyperosmolar Nonketotic ComaHyperosmolar nonketotic coma is a life-threatening complication of hyperosmolar hyperglycemic nonketotic syndrome (HHNS), in which your body tries to get rid of excess blood glucose by passing it through your urine. In severe cases, seizures, coma, and death may occur.SymptomsThe symptoms include:
- Very high blood glucose
- Dry mouth
- Warm, dry skin
- Absence of sweating
- Leg cramps
- Vision loss
- Weakness or strange movements on one side of the body with or without seizures
- Frequent urination
BlindnessChronic high blood glucose levels, as well as high blood pressure , can lead to damage to tiny blood vessels in the retina of the eye. This damage, called diabetic retinopathy, can occur over a long period of time. Cataracts and glaucoma (two other common eye conditions) occur more often and at a younger age in people with type 2 diabetes than in people without this disease. Signs of eye damage include:
- Blurry or double vision
- Halos, flashing lights, or black spots
- Dark or floating spots
- Pain or pressure in one or both of your eyes
- Trouble seeing things
Kidney DiseaseBetween 20%-40% of people with diabetes develop diabetic nephropathy, a form of kidney damage.High blood glucose levels and high blood pressure damage the kidney's small blood vessels, called capillaries. These capillaries are responsible for filtering waste out of the blood. This damage allows protein to leak out of the blood and causes wastes that should be excreted with the urine to build up in your blood. Having small amounts of protein in the urine is called microalbuminuria, the first sign of kidney damage. As damage continues, more protein is leaked and more wastes build up. Having larger amounts of protein in the urine is called proteinuria or macroalbuminuria. This damage can eventually progress to kidney failure , which requires dialysis or a kidney transplant .
Heart Disease and StrokePeople with type 2 diabetes are more likely to have heart disease or stroke compared to people who do not have diabetes. The most common form of heart disease is called coronary artery disease (CAD), blockage of the arteries that bring oxygen-rich blood to the heart muscles. This condition can lead to:
- Chest pain ( angina )—This pain or pressure typically starts in your chest and radiates to your arms (especially the left). This type of pain may appear when you exercise or after eating a large meal and it may get better when you rest.
- Cardiomyopathy —This is a general weakening of the heart muscle caused by narrowed, small blood vessels that decrease the blood flow through the heart. This can progress and cause heart failure .
- Heart attack—This is caused by the blockage of a blood vessel in or near your heart. As a result, part of your heart muscle does not receive oxygen and the essential nutrients it needs to function, so it stops working and dies. Symptoms of a heart attack include: chest pain, pressure feeling, nausea, indigestion, extreme weakness, and sweating.
- Sudden weakness or numbness of your face, arm, or leg on 1 side of your body
- Sudden confusion, trouble talking, or trouble understanding
- Sudden lightheadedness, loss of balance, or trouble walking
- Sudden trouble seeing in 1 or both eyes or sudden double vision
- Sudden severe headache
Nerve DiseaseDiabetes can also cause mild-to-severe nerve damage, called diabetic neuropathy . Having high blood glucose for many years can damage the blood vessels that bring oxygen to the nerves. High blood glucose can also damage the covering on the nerves. Damaged nerves may stop sending messages. Or, they may send messages too slowly or at the wrong times. This can lead to symptoms that range from pain or tingling, to numbness and loss of feeling. The longest nerves in the body are often affected first, leaving the hands and feet more susceptible to neuropathy. The combination of repeated injury, poor blood flow, and poor healing leads to a greater risk of foot infections that are often difficult to treat. In severe cases, when circulation is poor and antibiotics fail to cure the infection, foot or leg amputations may be necessary. Other, less severe consequences of nerve damage include:
- Drop in blood pressure when you stand
- Diarrhea at night
- Difficulty in emptying your bladder
- Erectile dysfunction
Lower Your Risk of ComplicationsTake these steps to promote your health:
- Have regular checkups even if you feel fine. Your doctor can often spot early signs of complications.
- Strive to keep your blood glucose levels, hemoglobin A1c (HbA1c) levels, blood pressure, and cholesterol levels within a healthy range at all times. Work with your doctor to determine which levels are safe for you.
- Do not smoke. If you do smoke, talk with your doctor about how you can quit.
- Get vaccinated against the flu and pneumonia .
- Have a regular exercise routine.
- If you are overweight, talk to your doctor about a safe weight loss program.
- Tell your doctor if you have symptoms of any diabetes complications.
- Ask your doctor if there are any medications that you should take to prevent complications. For example, find out if daily aspirin therapy is right for you.
- Keep track of your moods and be alert for persistent depressive symptoms.
- Make lifestyle changes to lower your LDL cholesterol levels. Reduce the amount of saturated fat and cholesterol in your diet. If you are overweight, lose weight. Increase how much physical activity you do each day.
- If you do not have cardiovascular heart disease:
- The goal is to have LDL cholesterol level less than 100 mg/dl.
- If you are over age 40 years old and have at least 1 other risk factor for heart disease, treatment goal is a 30%-40% reduction of LDL regardless of baseline LDL levels.
- If you are younger than 40 years old with other risk factors for heart disease and lifestyle changes fail to achieve the desired lipid-lowering goals, the ADA recommends medication.
- If you have cardiovascular heart disease:
- The ADA recommends statins to reduce LDL 30%-40% from original values.
- Lowering LDL cholesterol to below 70 using a higher dose of a statin isan option.
- Lower triglycerides to less than 150 mg/dl and raising high-density lipoprotein (HDL) cholesterol to over 40 mg/dl in men and over 50 mg/dl in women are other ADA treatment goals.
- All adults should eat fish at least twice weekly.
- If you have coronary heart disease, you should receive at least 1 gram of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) combined every day.
- EPA plus DHA supplement (such as 2-4 grams) is useful in lowering triglyceride levels by 20%-40%.
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Heart disease. American Diabetes Association website. Available at: http://www.diabetes.org/living-with-diabetes/complications/heart-disease. Accessed August 29, 2013.
Hyperosmolar hyperglycemic crisis. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed.ebscohost.com/about/about-us. Updated January 12, 2013 Accessed August 29, 2013.
Hypoglycemia. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed.ebscohost.com/about/about-us. Updated August 23, 2013 Accessed August 29, 2013.
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Stroke. American Diabetes Association website. Available at: http://www.diabetes.org/living-with-diabetes/complications/heart-disease/stroke.html. Accessed August 29, 2013.
What is hyperosmolar hyperglycemic nonketotic syndrome (HHNS)? American Diabetes Association website. Available at: http://www.diabetes.org/living-with-diabetes/complications/hyperosmolar-hyperglycemic.html. Updated August 21, 2013. Accessed August 29, 2013.
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- Reviewer: Kim A. Carmichael, MD, FACP
- Review Date: 09/2014
- Update Date: 12/15/2014