When blood glucose (sugar) levels are out of the normal range, complications may develop. These include the following:
Careful control of your blood glucose levels may lower your chance of developing some of these complications. Ask your doctor if there are medications that you should take to further reduce your risk.
Hypoglycemia 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:
Hypoglycemia can be managed if you recognize the symptoms and treat them right away. The symptoms include:
If you think you have hypoglycemia, test your blood with a blood glucose monitor. If the glucose level is below the range your doctor said was safe, then treat hypoglycemia. Even when you recognize the symptoms, it is best to use the glucose monitor to make sure that the symptoms you have are really due to hypoglycemia.
Safety ranges for glucose levels vary from person to person. The ranges are based on your age and medical conditions. If you do not know what your safe blood glucose range is, ask your doctor.
The goal of treating hypoglycemia is to quickly raise your blood glucose level to within your safe range. Ask your doctor what the best method of quickly treating hypoglycemia is for you. Common methods of self-treating hypoglycemia include eating or drinking some form of sugar, such as:
To be prepared, you should always have some type of sugar with you. Wait 15 minutes after eating, then retest your glucose level. If it is still too low, repeat the treatment. If you pass out from hypoglycemia, you will need emergency treatment. At the hospital, the doctor may give you an injectable hormone called glucagon. Your doctor may also give you a prescription for glucagon if you are at risk of hypoglycemia.
If you have symptoms or episodes of hypoglycemia, talk to your doctor. Also, review your medication to see if it needs to be adjusted. Your doctor can help you to find ways to prevent hypoglycemia.
Long-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:
Hyperglycemia should be treated right away to avoid further complications. The symptoms include:
If hyperglycemia is not promptly treated, it can lead to life-threatening ketoacidosis. This condition happens when glucose levels are so high that very little sugar is available in the cells for energy. The body starts breaking down stored fat for energy. The by-products of this fat breakdown are ketone bodies, acids that build up in the blood and cause ketoacidosis. The condition is more common in type 1 diabetes, but it may occur rarely in type 2 diabetes.
Hyperosmolar 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.
The symptoms include:
It is important to seek medical attention right away if you think you have symptoms of hyperosmolar nonketotic coma.
Chronic 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:
Some people do not have any symptoms until the damage is significant. Therefore, it is essential to see your eye doctor regularly. Diabetic retinopathy can be treated with laser therapy or surgery. Quitting smoking and controlling your blood pressure are important preventive measures.
Between 20%-40% of people with diabetes develop diabetic nephropathy, a form of kidney damage.
High blood glucose levels and high blood pressure damage the kidneys' 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.
People 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:
A stroke can also happen as a result of blood not being able to reach the brain. This may be due to a blockage in a blood vessel. Symptoms of a stroke include:
Diabetes 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:
Your feet are especially vulnerable to the complications of type 2 diabetes. Damage to the peripheral nerves, which go to the arms, hands, legs, and feet, can impair your experience of sensations, such as pain, heat, and cold.
In addition to nerve damage, type 2 diabetes can also cause a decrease in blood flow. Therefore, if you have a blister or sore on your foot, you may not feel it because of the neuropathy. Because of the lack of sensation, this area on your foot may be continually re-injured. It is essential to wash and examine your feet daily. If your doctor recommends it, you may want to use a special skin thermometer to check the temperature of your feet. High foot temperature may be a sign of injury or inflammation.
Take these steps to promote your health:
ACE inhibitors are the name of a class of medications that are generally used to treat high blood pressure and heart failure. These medications work by blocking angiotensin-converting enzyme. This is a protein that helps the body make angiotensin, which in turn raises blood pressure. Thus, by blocking this enzyme the drug works to lower blood pressure.
ACE inhibitors are generally recommended for patients with diabetes who have high blood pressure, cardiovascular disease, or kidney damage. This medication may decrease the risk of further kidney damage, and reduce the risk of death and heart attacks.
Talk to your doctor about whether ACE inhibitors are right for you.
The American Diabetes Association (ADA) offers these guidelines on LDL "bad" cholesterol and coronary heart disease:
The American Heart Association (AHA) offers these recommendations on omega-3 fatty acids:
People with diabetes are at increased risk of getting cardiovascular disease. Taking aspirin may help decrease the risk of having a heart attack in patients who are at risk for heart disease or for those who have heart disease. Talk to your doctor about whether the benefits of daily aspirin outweigh the risks in your case. Aspirin can cause bleeding and interacts with other drugs.
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Heart disease. American Diabetes Association website. Available at: http://www.diabete... . 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.diabete... . Accessed August 29, 2013.
What is hyperosmolar hyperglycemic nonketotic syndrome (HHNS)? American Diabetes Association website. Available at: http://www.diabete... . Updated August 21, 2013. Accessed August 29, 2013.
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2/7/2008 DynaMed Systematic Literature Surveillance https://dynamed.ebscohost.com/about/about-us : Lavery LA, Higgins KR, Lanctot DR, et al. Home monitoring of foot skin temperatures to prevent ulceration. Diabetes Care. 2004;27:2642-2647.
2/13/2008 DynaMed Systematic Literature Surveillance https://dynamed.ebscohost.com/about/about-us : For safety, NHLBI changes intensive blood sugar treatment strategy in clinical trial of diabetes and cardiovascular disease. NIH News. National Institutes of Health website. Available at: http://www.nih.gov/news/health/feb2008/nhlbi-06.htm . Accessed August 29. 2013.
2/21/2008 DynaMed Systematic Literature Surveillance https://dynamed.ebscohost.com/about/about-us : Major international diabetes study does not confirm increased risk of death reported by US trial. Action in Diabetes and Vascular Disease: PreteraAx and DiamicroN MR Controlled Evaluation (ADVANCE) website. Available at: http://www.advance... . Accessed August 29, 2013.
4/10/2008 DynaMed Systematic Literature Surveillance https://dynamed.ebscohost.com/about/about-us : The ONTARGET investigators. Telmisartan, ramipril, or both in patients at high risk for vascular events. N Engl J Med. 2008;358(15):1547-1559.
6/18/2008 DynaMed Systematic Literature Surveillance https://dynamed.ebscohost.com/about/about-us : ADVANCE Collaborative Group. Intensive blood glucose control and vascular outcomes in patients with type 2 diabetes. N Engl J Med. 2008;358:2560-2572.
Last reviewed September 2013 by Kim Carmichael, MD
Last Updated: 9/30/2013