How diabetes can harm your body

Understand some of the complications that may come from having diabetes—and what you can do to help prevent them.

doctor checking knee reflexes

Updated on September 20, 2024.

Diabetes is a chronic disease that has far-reaching implications for your overall health. When you have diabetes, your body doesn’t make enough insulin, or doesn’t respond to the insulin it has sufficiently. Insulin is a hormone that helps glucose (blood sugar) get into your cells where it provides a source of fuel. When the glucose stays in the bloodstream instead of going into your cells, it can become elevated and cause harm in a wide range of ways. Over time, this leads to problems called diabetic complications.

Diabetic complications

Diabetic complications are a significant cause of additional disease—even death—in people with diabetes.

“There are two major drivers for complications in diabetes,” says Darria Long Gillespie, MD, an emergency department physician and clinical assistant professor at the University of Tennessee School of Medicine. “The first of these is hyperglycemia, or elevated blood glucose. This means that your cells, particularly those in the blood vessels, eyes, kidneys, and nerves, are constantly being bathed in high levels of blood glucose. This leads to the release of free radicals and proteins that damage cells.” Free radicals are unstable molecules that can cause a chain reaction and lead to cell damage.

The other driver is atherosclerosis, or the hardening and narrowing of the artery walls. “Diabetes increases the risk of atherosclerosis, which can lead to heart attacks and stroke,” Dr. Gillespie says. This risk is substantial. People with diabetes are nearly twice as likely as those who don’t have diabetes to develop heart disease and two to four times more likely to die from it. In fact, two-thirds of patients with diabetes will die of heart disease or stroke.

Diabetic retinopathy is probably the most common blood vessel-related complication of diabetes. Retinopathy is a problem with the retina, or the light-sensitive area in the back of the eye. Diabetic retinopathy accounts for about 10,000 new cases of blindness every year in the United States. People with diabetes are also 40 percent more likely to develop glaucoma—eye diseases that affect the optic nerve and can cause blindness—and 60 percent more likely to develop cataracts, or clouding of the lens of the eye.

Diabetes also harms other organs. It’s a leading cause of kidney (renal) disease and nerve damage through the body—particularly the nerves in your lower extremities (a condition known as neuropathy). Neuropathy can increase the risk of foot or lower leg amputation. More than 80 percent of amputations in people with diabetes happen after a foot ulceration or injury.

People with diabetes may also have skin problems, which are sometimes an early warning sign of diabetes. Fortunately, most are preventable and treatable if caught early. See your healthcare provider (HCP) if you notice changes in your skin, such as excessive dryness, cracking, broken skin, redness or warmth, which may be signs of decreased circulation or even infection.

Preventing diabetic complications

“Good blood sugar control is the first key action for someone with diabetes,” says Gillespie. “It will prevent complications or slow the progression if you’re already starting to develop them.”

Timing when you eat, exercise, and when you take your insulin or diabetes medications can help maintain consistent blood glucose levels. Your HCP may recommend long-acting insulin—alone or in combination—which doesn’t start to work quite as fast, but does last longer without the typical peak and decline of shorter-acting types of insulin.

“Since elevated blood pressure is a significant contributor to heart disease and stroke, people with diabetes need to control their blood pressure even more strictly than people without diabetes,” Gillespie says. High blood pressure makes your heart work extra hard, which can lead to heart and blood vessel damage. Ask your HCP if you should take medications for blood pressure or cholesterol, which is also a risk factor for heart disease and is often high in people who have diabetes.

“Never underestimate the impact you can have by changing your lifestyle,” says Gillespie. “A regular exercise regimen will lower your blood pressure and naturally improve glucose control. Adhering to a healthy diet can also help manage your weight and reduce your risk for metabolic syndrome and high glucose.” Metabolic syndrome is a cluster of symptoms, including too much body fat around the abdomen and high blood pressure, which raise your risk for both heart disease and diabetes.

Furthermore, if you smoke, quit. Smoking and diabetes both narrow blood vessels, raising your risk for heart disease, as well as lower leg infections and ulcers that could lead to amputation.

Finally, a good diabetes management program also includes regular screenings. See your eye doctor for an annual comprehensive eye exam and your primary care doctor or a podiatrist who can check your feet and legs for peripheral neuropathy. The American Diabetes Association also recommends annual screening for kidney disease, as well as blood pressure and cholesterol screenings. Early diagnosis is critical for preventing long-term—often irreversible damage—from diabetes complications.

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