What Diabetes Can Do to Your Body

If you have diabetes, work closely with your doctor to manage your blood sugar levels.
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Diabetes complications can affect systems throughout your body. That's because the disease can damage the blood vessels that supply these systems, caused by high levels of sugar in your blood. Your brain, eyes, heart, kidneys and nerves can all be affected by problems caused by diabetes. Here's how.

Read more:The Major Causes of Type 2 Diabetes — and Who's Most at Risk


Your Brain and Eyes

Damage to blood vessels caused by high blood sugar — hyperglycemia, in medical terms — is due to narrowing and thickness of arteries, called atherosclerosis, which can cut off blood supply to your brain, leading to stroke, says the U.S. Centers for Disease Control and Prevention (CDC).

"If you have diabetes, you have a four-time higher risk of stroke," says Mary Vouyiouklis Kellis, MD, an endocrinology specialist in the Department of Endocrinology, Diabetes and Metabolism at the Cleveland Clinic.


As for your eyes, "diabetes causes visual problems due to bleeding and swelling inside the eye," Dr. Kellis says. "Fluid can also build up inside the lens of your eye, causing blurred vision." People with diabetes also have an increased risk for cataracts and glaucoma, she says.

In addition, small blood vessel damage — called diabetic retinopathy — leads to gradual loss of vision, and is one of the leading causes of blindness.

These possible effects make it important for people with diabetes to have regular eye exams, says the U.S. National Library of Medicine.


Your Heart and Kidneys

In addition to upping the risk for stroke, atherosclerosis also makes people with diabetes more likely to have a heart attack, CDC reports. And, Dr. Kellis says, "diabetes also causes high blood pressure, which can put a strain on your heart and cause heart failure."

Heart disease is a major cause of death in people with diabetes, making it important to control other heart disease risk factors, like high blood pressure and cholesterol, along with blood sugar, notes the Cleveland Clinic.


As for diabetic kidney disease, it's caused by damage to small blood vessels inside your kidneys. "Your kidneys filter waste from your blood," Dr. Kellis says. "Diabetes damages the filter system and lets proteins pass out through your urine. It is like having a pasta strainer that lets the pasta pass through."

Detecting protein in the urine is an early sign of diabetic kidney disease, which is the leading cause of kidney dialysis and kidney transplant. The Cleveland Clinic says that people with diabetes should have their urine checked for protein once a year. Symptoms of kidney disease can include swelling of your hands, face and feet, along with itching and drowsiness.

Your Nerves

"When diabetes damages nerve endings, it is called peripheral neuropathy," Dr. Kellis says. "This damage causes numbness in your feet that can lead to an infected foot ulcer."

Diabetic neuropathy, the nerve damage caused by diabetes, about one-half of people with diabetes, says the National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms may depend on which nerves are affected, Mayo Clinic notes. For example, Mayo says peripheral neuropathy, the most common type, can cause sharp pain, tingling or burning, and numbness.

The Cleveland Clinic notes that diabetic peripheral neuropathy can lead to amputation of your toes, foot or leg. However, regular inspection of your feet and good foot care can greatly reduce the risk of amputation, CDC points out.

Other Effects of Diabetes

"In addition to the effects of diabetes on your brain, eyes, heart, kidneys and peripheral nerves, there are other important effects on your body," Dr. Kellis says. For instance:

  • Your body defense system may be weakened by diabetes, making it easier to get an infection and harder to fight off infection.
  • Your digestive system may slow down. This can cause slowing of digestion with gas, bloating and nausea, a condition called gastroparesis.
  • Nerve damage can affect the nerves that regulate blood pressure, which can cause your blood pressure to go up or down unpredictably.
  • Diabetes can make you feel tired and drained of energy.

To prevent or delay the effects that diabetes can have on your body, work closely with your doctor to achieve good control of your blood sugar and be screened for early signs of damage.

Read more:A Healthy Diet Can Help Manage Type 2 Diabetes — These Are the Best and Worst Foods to Eat


Is This an Emergency?

If you are experiencing serious medical symptoms, please see the National Library of Medicine’s list of signs you need emergency medical attention or call 911. If you think you may have COVID-19, use the CDC’s Coronavirus Self-Checker.