Preventing Diabetic Complications

What are diabetic complications?

Diabetic complications are health problems caused by diabetes. Diabetes causes your blood sugar level to be higher than normal. Over time, high blood sugar levels can damage your blood vessels and nerves. This damage can cause problems in many areas of the body. This handout explains common diabetic complications and how to prevent them.

Nerve damage

Nerve damage (also called diabetic neuropathy) makes it hard for your nerves to send messages to the brain and other parts of the body. If you have nerve damage, you may lose feeling in parts of your body or have a painful tingling feeling.

Neuropathy most often affects the feet and legs. If you have neuropathy, you may not be able to feel a sore on your foot. The sore can become infected and, in serious cases, the foot may have to be amputated (removed). People who have neuropathy may continue walking on a foot that has damaged joints or bones. This can lead to a condition called Charcot foot that causes the injured foot to become deformed. However, this problem can often be avoided.

If you have diabetes, check your feet every day. If you see swelling and redness and feel warmth in your foot, see your doctor immediately. These can be signs of Charcot foot. Your doctor should also check your feet at least once a year.

Warning signs of nerve damage

Call your doctor if you have:

  • Loss of feeling (numbness)
  • Sharp pain or tingling feeling
  • Sores on your feet
  • Muscle weakness
  • Burning feeling
  • Inability to get an erection (in men)

Eye problems

The retina is the part of the eye that is sensitive to light and helps you see. Diabetes can damage and weaken the small blood vessels in the retina. This damage is called diabetic retinopathy.

When the blood vessels are weak, they can leak fluid. This causes swelling in the eye that blurs your vision. If retinopathy gets worse, it may lead to blindness by causing your retina to break away from the back of the eye.

Laser surgery can often be used to treat or slow down retinopathy, especially if the problem is found early. People who have diabetes should have an eye exam once a year.

Warning signs of eye problems

Call your doctor if you have:

  • Blurred vision for more than 2 days
  • Sudden loss of vision in 1 or both eyes
  • Black spots, cobwebs or flashing lights in your vision
  • Redness in your eye
  • Pain or pressure in your eye

Kidney damage

Diabetes can also damage the blood vessels in your kidneys so they can't filter out waste. This damage is called diabetic nephropathy. Some people who have nephropathy will eventually need dialysis (a treatment that eliminates waste from the blood) or kidney transplant.

The risk for nephropathy is increased if you have both diabetes and high blood pressure, so it is important to control both of these conditions.

Protein in the urine is usually the first sign of nephropathy. This should be checked yearly. If your doctor notices early signs of this, he or she can put you on medicine that helps protect your kidneys from damage.

Heart disease and stroke

People with diabetes are at greater risk for heart disease and stroke, The risk is even greater for people who have diabetes and smoke, have high blood pressure, have a family history of heart disease or are overweight.

Heart disease is easiest to treat when it is caught early. It is very important to see your doctor on a regular basis. He or she can test for early signs of heart disease or stroke.

The recommended cholesterol level for a person with diabetes is the same as for someone with heart disease. If your cholesterol is higher than the recommended level, your doctor will talk to you about lifestyle changes and medication to help get your cholesterol under control.

What can I do to prevent or delay diabetic complications?

To prevent problems, keep your blood sugar level as close to normal as possible and follow your doctor's instructions. The following are some other tips:

  • Eat a variety of healthy foods. Avoid foods that are high in fat and sugar.
  • Maintain a healthy weight. If you're overweight, your doctor can give you advice on how to lose weight safely.
  • Control your blood pressure and cholesterol levels.
  • Be physically active on a regular basis.
  • Quit smoking.
  • See your doctor regularly, even when you feel fine. Your doctor will check for early signs of complications.
  • Call your doctor right away if you have any of the warning signs listed in this handout.

More Information

For more information talk to your doctor.

Other Organizations


Written by editorial staff.

American Academy of Family Physicians

Reviewed/Updated: 11/06
Created: 03/99