Complications of Type 1 DiabetesEn Español (Spanish Version)
When blood glucose levels are out of the normal range, they cause complications. These include the following:
In the short-term:
In the long-term:
Careful control of diabetes can reduce your risk of complications.
Hypoglycemia is low blood sugar. Sometimes it is called an "insulin reaction." It can be caused by any of the following:
- Taking too much insulin
- Skipping a meal or eating a smaller meal than usual without adjusting your insulin dose
- Exercising harder or longer than normal without adjusting your insulin dose
Hypoglycemia can be managed fairly easily if you recognize the symptoms and treat it right away. The symptoms of hypoglycemia include:
- Pale skin color
- Sudden moodiness or behavior change, such as crying for no apparent reason
- Clumsy or jerky movements
- Confusion or difficulty paying attention
- Tingling sensations around the mouth
- Rapid heart rate
If you think you are hypoglycemic, test your blood with your blood glucose monitor. If your blood glucose level is below your normal range, treat the hypoglycemia. (If you don't know what your normal blood sugar range is, ask your doctor). Or, if you recognize the symptoms of low blood sugar, you may want to treat it immediately, without waiting to test.
The goal of treating hypoglycemia is to quickly raise your blood glucose level to within your normal range. This can be done by eating or drinking some form of sugar, such as:
- Glucose tablets
- ½ cup of fruit juice
- 5-6 pieces of hard candy
To immediately treat hypoglycemia, you should always have some type of sugar with you.
Wait 15-20 minutes after eating the sugar, and then retest your blood glucose. If it is still too low, repeat the treatment.
If you pass out from hypoglycemia, you will need immediate treatment. This can be an injection of glucagon. Glucagon is a hormone that raises the level of blood sugar. Ask your doctor for a prescription so that you can have it on hand. Also, teach your family members and coworkers how to administer the glucagon. If glucagon is not available, you should be taken to the hospital for emergency treatment. Once successfully treated, you need to try to identify the reasons which cause the condition so that you know how to prevent future recurrences.
Hyperglycemia is high blood sugar. Long-term hyperglycemia is the major cause of many of the long-term complications that occur in people with diabetes (discussed below). Hyperglycemia occurs when you do not have enough insulin to dispose of the glucose in your body. It can be caused by any of the following:
- Taking too little insulin
- Eating a larger meal than usual without adjusting your insulin dose
- Exercising less than you planned without adjusting your insulin dose
- Stress from an illness (eg, a cold or flu, or stress from factors in your daily life)
Hyperglycemia should be treated immediately to avoid further complications. The signs and symptoms include:
- High blood sugar—Ask your doctor how often you should check your blood sugar.
- High levels of sugar in your urine—Ask your doctor if you should be monitoring your urine.
- Frequent urination (polyuria)
- Increased thirst (polydipsia)
- Blurred vision
If hyperglycemia is not promptly treated, it can lead to ketoacidosis, which is also known as diabetic coma. When blood sugar 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 fat breakdown are ketone bodies, which are acids that build up in the blood and cause ketoacidosis.
If your blood sugar is greater than 240 mg/dl (13.3 mmol/L), check your urine for ketones. If you have ketones, you will need either to consult your doctor immediately or follow a previously agreed plan for managing ketosis. Some experts recommend that you do not exercise if urine contains ketones. In most cases, the treatment for high blood sugar and urine ketones will be additional insulin.
If you often have hyperglycemia, talk with your doctor about the best way to treat it. You may need to adjust your diet, your insulin regimen, or the amount of exercise you do.
People with type 1 diabetes can develop ketoacidosis, a serious condition that does not happen in people with type 2 diabetes . When your body is not getting enough insulin, sugar cannot get into the cells to generate energy. When this happens, the body starts breaking down stored fat for energy. The by-products of fat breakdown are ketone bodies, which are acids that build up in the blood that can cause ketoacidosis. The most common reasons for your body to generate ketones are:
- Taking too little insulin—This occurs especially when you are sick with an infection because the body may need more insulin. This is the setting in which ketoacidosis typically occurs.
- Eating too little or missing a meal—Again, this can often occur when you are sick and is usually associated with low or normal blood sugar.
- Taking too much insulin, causing low blood sugar, and making the body burn fat to get energy—This too is usually associated with low or normal blood sugar.
Signs and symptoms that signal ketoacidosis include:
- High levels of ketones in the urine or blood
- Fruity smell to the breath
- Shortness of breath
- Nausea and vomiting
- Dry mouth or signs of dehydration
- Abdominal pain
- Reduced mental function and alertness
Ask your doctor for a plan on when to measure and call about ketones. Ketoacidosis is a life-threatening condition and needs immediate medical treatment.
Chronic high blood sugar, as well as high blood pressure, can damage tiny blood vessels in the retina of the eye. Diabetes is the most common cause of blindness in individuals between the ages of 20-60 in the US. This damage, called diabetic retinopathy, usually occurs over a long period of time. Signs of eye damage include:
- Blurry or double vision
- Rings, flashing lights, or blank spots
- Dark or floating spots
- Pain or pressure in one or both of your eyes
- Trouble seeing things out of the corners of your eyes
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, called photocoagulation, or surgery. Quitting smoking and controlling your high blood pressure are also important preventive measures.
Other eye conditions occur almost twice as often and at a younger age in people with type 1 diabetes than in people without this disease. These are cataract and glaucoma . A cataract is a cloud over the lens of your eye. Your lens, which is usually clear, focuses light onto the retina, but a cataract makes your vision cloudy. This condition can be treated with surgery.
Glaucoma is caused by increased pressure in the eye that damages your eye's main nerve—the optic nerve. The damage first causes you to lose sight from the sides of your eyes. Without treatment, you can go blind. Glaucoma can be treated with special eye drops or laser surgery.
Between 20%-40% of people with diabetes have kidney damage after 20 years, which is known as diabetic nephropathy.
High blood sugar and high blood pressure damage the kidneys’ glomeruli, which 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. Two classes of drugs, angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers, can reduce the leakage of protein in the urine and delay the onset of diabetic kidney disease.
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. Eventually, this damage can progress to kidney failure, which requires dialysis or a kidney transplant. Restricting protein intake in diabetic patients with chronic renal failure can lower the death rates.
People with type 1 diabetes are 2-4 times more likely to have heart disease and to die from heart disease as people without diabetes.
Having diabetes can cause your blood cholesterol levels to rise, leading to clogged, narrowed arteries, called atherosclerosis—Clogged arteries make it more difficult for blood to carry oxygen and other essential nutrients to vital organs and tissues, such as your heart, and can cause:
- Chest pain (also called angina)—This pain or pressure feeling usually starts in your chest and radiates to your arm and may worsen when you exercise or after a full meal.
- Heart attack—This is caused by the blockage of a blood vessel that supplies oxygen and other essential nutrients to your heart. When part of your heart muscle doesn't receive the nutrients it needs to function, it stops working. Symptoms include: chest pain or pressure feeling, nausea, indigestion, extreme weakness, and sweating.
- Cardiomyopathy—This is a weakening of the heart muscle caused by the narrowing of small blood vessels throughout the heart.
Type 1 diabetes makes you 2-4 times more likely to have a stroke . A stroke is caused by a blockage of blood flow to the brain. The effects of a stroke depend on the part of your brain that is damaged and may include:
- Sudden weakness or numbness of your face, arm, or leg on one side of your body
- Sudden confusion, trouble talking, or trouble understanding
- Sudden dizziness, loss of balance, or trouble walking
- Sudden trouble seeing in one or both eyes or sudden double vision
- Sudden severe headache
About 70%-80% of people with diabetes have mild to severe forms of diabetic nerve damage, called diabetic neuropathy. Having high blood sugar for many years can damage the blood vessels that bring oxygen to nerves. High blood sugar can also hurt the covering on the nerves. Damaged nerves may stop sending messages. Or, they may send messages too slowly or at the wrong times.
Nerve damage due to diabetes could manifest as:
- A drop in blood pressure upon standing up
- Diarrhea at night
- Difficulty swallowing
- Neurogenic bladder with dribbling, weak stream, or hesitancy
- Erectile dysfunction
Your feet are especially vulnerable to the effects of type 1 diabetes. Damage to the peripheral nerves—which go to the arms, hands, and legs, as well as the feet—can impair your experience of sensations such as pain, heat, and cold. In addition to nerve damage, type 1 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 neuropathy. And then, because of poor blood flow, the sore may not heal and be at a higher risk of becoming infected. In severe cases, this nerve damage can lead to foot and leg amputations. Therefore, it is essential to wash and examine your feet daily.
According to two recent studies, if you are at high risk for diabetic foot ulcers, checking the temperature of your feet—using an infared skin thermometer—reduces the number of ulcers. The TempTouch thermometer used in the study costs $150.*1*2
Reduce Your Risk of Complications
Have Regular Checkups Even If You Feel Fine
Your doctors can often spot early signs of complications. Perhaps more importantly, most of the complications listed above can be prevented be following recommended standards for diabetic care.
If you've had diabetes for several years, do at least the following:
- Frequent (every 3-6 months) measurement of glycosylated hemoglobin to ensure effective treatment (in most cases the result should be under 6.5%-7.0%)
- Yearly expert examination of the eyes using drops to dilate the pupils
- Periodic examination of feet with a nylon "monofilament" to determine that sensation is normal
- Yearly examination of the urine to detect microalbuminuria
- Careful control of blood pressure (must be under 135/85), low density lipoproteins (under 100 mg/dL [2.6 mmol/L]), and triglycerides to reduce long-term risk of heart disease and stroke
- Immunization with influenza and pneumococcal vaccine to reduce risk of pneumonia or other complications
- Taking low dose aspirin every day (probably for adults only)
Unfortunately, many doctors fail to help their patients adhere to these standards. As a result, complication rates for diabetes are higher than they might otherwise be.
Strive to Keep Your Blood Sugar and Blood Pressure Within a Healthful Range
It is very important that you know what these normal ranges are. For blood sugar, the pre-meal level should be less than 110 mg/dl ( 6.1 mmol/L) and the post-meal less than 140 mg/dl (7.7 mmol/L). Your blood pressure should be less than 130 mmHg systolic (upper number) and less than 85 mmHg ( the lower number).
Tell your doctor if you have any of these warning signs:
- Vision problems, such as blurriness or spots
- Pale skin color
- Numbness or tingling feelings in hands or feet
- Repeated infections or slow healing of wounds
- Chest pain
- Vaginal itching
- Constant headaches
- Cuts or blisters on your feet
- Don't smoke; if you smoke, quit.
- Regular exercise (ie, aerobic exercises three to five times a week for 20-60 minutes each time). Make sure that your doctor approves this before you start. Remember to wear your diabetes identification bracelet or shoe tag.
American Diabetes Association website. Available at: http://www.diabetes.org/home.jsp.
American Dietetic Association website. Available at: http://www.eatright.org/cps/rde/xchg/ada/hs.xsl/index.html.
Hyperglycemic crises in diabetes. Diabetes Care . 2004(Supp 1);27:S94-102.
National Institute of Diabetes & Digestive & Kidney Diseases website. Available at: http://www.niddk.nih.gov/.
Perkins BA, Ficociello LH, Silva KH, et al. Regression of microalbuminuria in type 2 diabetes. New Engl J Med. 2003;348:2285-2295.
Physical activity/exercise and diabetes. Diabetes Care. 2004; 27(Suppl 1):S58-62.
*12/7/2008 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed/what.php: Armstrong DG, Holtz-Neiderer K, Wendel C, Mohler MJ, Kimbriel HR, Lavery LA. Skin temperature monitoring reduces the risk for diabetic foot ulceration in high-risk patients. Am J Med. 2007;120:1042-1046.
*22/7/2008 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed/what.php: Lavery LA, Higgins KR, Lanctot DR, et al. Home monitoring of foot skin temperatures to prevent ulceration. Diabetes Care. 2004;27:2642-2647.
Last reviewed April 2007 by David Juan, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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