Key takeaways

Uncontrolled diabetes can lead to serious health complications, including heart disease, kidney damage, nerve damage, and issues with eyes and feet.
Regular medical appointments, medication adherence, and blood sugar monitoring are crucial for preventing and managing diabetes complications.
Lifestyle changes such as a healthy diet and regular exercise can significantly reduce the risk of diabetes complications.
Uncontrolled blood sugar levels are the main cause of diabetes complications, with cardiovascular disease being the most common.

In this article:

What are the complications of diabetes?
What causes diabetes complications?
How to prevent complications of diabetes

In this article

What are the complications of diabetes?
What causes diabetes complications?
How to prevent complications of diabetes

If you live with Type 1 diabetes or Type 2 diabetes mellitus, you are probably aware of the immediate side effects that occur if your blood sugar gets too high, such as racing heartbeat, nausea, blurred vision, and headaches. But what you may not realize is that if either of these types of diabetes is not controlled, it can lead to chronic health conditions over time. Common diabetes complications include cardiac issues, eye problems, kidney damage, neurological issues, and foot problems.

There’s hope, though. Most common complications of diabetes can be avoided by sticking to the care instructions provided by your healthcare provider, and by adopting lifestyle choices that help keep your blood sugars in check. Read on for what you should know about diabetes complications, including what causes them and how to prevent and avoid them.

What are the complications of diabetes?

Diabetes is a chronic health condition affecting more than 37 million Americans. It’s marked by the body’s inability to regulate blood sugar levels, leading to excess glucose in the body. When glucose gets too high, it can cause a variety of health problems. Some of these complications are acute (happening right away), but others are chronic (developing over time).

RELATED: Diabetes statistics

Acute vs. chronic diabetes complications

Acute diabetes complications include:

Hyperglycemia, or high blood glucose
Hypoglycemia, or low blood sugar
Diabetic ketoacidosis, a life-threatening complication that happens when you don’t have enough insulin

Chronic diabetes complications are health conditions that develop over a period of time, especially if your diabetes is not well-controlled. When diabetes is not controlled, it can affect all the organs in your body, says Hannah Goldberg, MD, a primary care physician at Mercy Personal Physicians. “Common organs affected by diabetes are the eyes, kidneys, blood vessels, heart, and brain,” Dr. Goldberg explains. “Uncontrolled diabetes can lead to strokes and heart attacks, as well as blindness and kidney failure requiring dialysis.” Let’s take a deeper look at how diabetes affects different organs in your body.

Eye problems

Diabetes can lead to a number of issues with your eyes, says Sherry Roberts, MPH, RDN, a certified diabetes care and education specialist. “Uncontrolled diabetes can lead to complications such as diabetic retinopathy, which impacts our eyes, and blindness may occur,” Roberts says. Diabetic retinopathy, which is caused by damage to the small blood vessels in the retina, is the most common cause of vision loss and vision impairment among working-age adults in the U.S. Diabetes can also lead to eye disease such as cataracts (clouding of the eyes) and glaucoma (increased fluid pressure to the eye).

Foot issues

Uncontrolled diabetes can lead to various foot complications. “It can cause foot and leg wounds that become infected and are difficult to heal,” says Dr. Goldberg. Sometimes amputation may be required in extreme cases. Diabetes can also cause nerve damage to the foot, resulting in symptoms such as numbness and tingling.

Heart problems

Diabetes can have a major impact on your heart. In fact, if you have diabetes, you are twice as likely to have heart disease. This increased risk of heart disease is because diabetes can affect the blood vessels and nerves that work with your heart. For example, diabetes can cause increases in blood pressure as well as a build-up of LDL, or “bad” cholesterol. It can also cause an unhealthy number of triglycerides (also called “lipids,” a type of fat in your bloodstream).

Kidney issues

Diabetes can sometimes have severe effects on your kidneys, says Dr. Goldberg. “Over time, the elevated blood glucose can deposit in blood vessels in the kidneys, causing the kidneys to lose their ability to filter your blood and make urine,” she says. “This can necessitate the need for dialysis or kidney transplant.” About a third of people with diabetes develop kidney disease. People with uncontrolled diabetes are also at a higher risk for developing diabetic nephropathy, which can lead to kidney damage.

Nerve damage

Diabetic neuropathy (nerve damage) is another common diabetes complication. It can cause numbness and tingling in the hands and feet, but it can potentially impact other nerves in the body as well. “For example, the nerves that control digestion can be damaged and lead to a condition called gastroparesis,” she explains. “Also, the nerves that control blood pressure and your body’s ability to cool can be damaged in neuropathy.” Finally, sexual arousal can be impacted and may lead to erectile dysfunction due to blood flow problems, Roberts says.

What is the most common complication of diabetes?

According to a 2019 study published in the European Journal of Preventive Cardiology, cardiovascular disease is the most common diabetes complication, affecting people with Type 2 diabetes most commonly. People with diabetes are about two to four times more likely to develop heart disease than people without diabetes, according to this study. This is especially true for people who aren’t actively controlling their blood sugar.

The good news is that these days more people are living full lives with diabetes, assures Justine Chan, RD, a certified diabetes educator. Still, diabetes is associated with a 75% increased death rate, mostly due to heart disease complications. “According to the World Health Organization, in 2019, 1.5 million deaths occurred as a result of having diabetes,” Chan notes. “Diabetes complications arise not only from high blood sugars, but also from highly processed diets, elevated blood pressure, cholesterol, smoking, high levels of stress, and mental health issues.”

What causes diabetes complications?

“The main cause for diabetes complications is uncontrolled diabetes,” says Roberts. It’s recommended that people keep their A1C (a test measuring blood glucose levels) at less than 6.5% to prevent diabetes complications, says Roberts. Lifestyle changes, such as a diabetes-friendly diet and daily exercise routine, can make a huge difference.

“Reducing the processed and simple sugar in the diet, like sugar sweetened beverages, and reducing the intake of sweets and treats will greatly improve blood sugar control,” Roberts describes. “Being active with a 30-minute walk at a moderate pace five days a week will also help keep blood sugars in range.” She also recommends maintaining a healthy weight, and says that even a 5% to 10% reduction in body weight can positively control blood sugar.

In addition to uncontrolled blood sugar, unhealthy eating, and sedentary lifestyle, other risk factors can put you at greater likelihood of developing diabetes complications, including:

Obesity or being overweight
Being a smoker
Having high blood pressure
Having high cholesterol

How to prevent complications of diabetes

Here are the most effective ways to prevent diabetes complications.

1. Prevent disease onset in the first place

If you haven’t yet been diagnosed with diabetes, but have a strong family history of the disease, there are some things you can do to prevent the condition. This includes going to regular check-ups and getting your A1C monitored at each visit. “If it is trending upward, you should make sure you’re doing a great job focusing on eating lower carbohydrate and lower fat meals, and focusing more on healthy proteins, fruits, and vegetables,” Dr. Goldberg recommends.

2. Keep up with your medical appointments

If you’ve been diagnosed with diabetes, it’s imperative to see your healthcare provider regularly. “The most important step to prevent diabetes complications is to have regular follow-up with your diabetes team or primary care provider,” says Chan. “This way you have the support and accountability you need for your lifestyle goals, the resources to manage stress around the disease, and a checkpoint to ensure you are on the right medications.”

3. Take your medication as prescribed

Diabetes is often controlled with medication, such as insulin. But you have to take it when indicated, as prescribed by your healthcare provider. “Being proactive in your health care and monitoring blood sugars routinely will allow for treatment plans to be adjusted if needed before blood sugars get out of control,” Roberts says. Always reach out to your provider if you have any questions about your medications, or if your symptoms are not improving or getting worse.

4. Check your blood sugar regularly

Most diabetes management plans involve keeping close tabs on blood sugar. Regular glucose monitoring can help you avoid any harmful effects of the disease. “The best way to prevent diabetes complications is to manage blood sugars and keep them as close to the goal as possible,” says Roberts. But it goes beyond simple tests. You’ve also got to be an advocate for yourself and be in consistent communication with your provider about your numbers. It’s especially important to contact your provider if your blood sugar numbers are out of range, so that any adjustments to medication or other treatments can be made.

5. Keep up a healthy diet and exercise routine

It can’t be emphasized enough how powerful a smart eating and exercise routine can be for managing diabetes and keeping complications at bay. Chan’s tips include adopting diets that are proven to help manage diabetes, such as the DASH (Dietary Approaches to Stop Hypertension), low glycemic index diet, and the Mediterranean diet. “These diets have been shown to have beneficial effects on blood glucose, as well as cholesterol and blood pressure,” she says.

Managing diabetes involves eating a nutrient-dense diet, emphasizing fruits, veggies, whole grains, and lean proteins. The American Diabetes Association recommends the “Diabetes Plate Method,” which includes filling half of your plate with non-starchy vegetables, one quarter of the plate with protein, and one quarter with carbohydrates. In addition, there are certain foods that are best avoided if you are trying to stay healthy and avoid diabetes complications. Food to steer clear of—or only have in moderation—include:

Candy
Cookies and cake
Sweetened cereals
Canned fruit with sugar added
White bread
Pasta
Starchy vegetables (white potatoes, corn, peas)
Soda
Juice
Fast food

Chan also recommends aiming for 150 minutes of moderate physical activity per week, as well as resistance exercises two to three times per week. The weight loss that comes along with improved diet and exercise can help reduce risk of complications, and can even reverse prediabetes.

6. Prevent and treat gum disease

Diabetes and diabetes medications can increase the amount of glucose in saliva, which can feed harmful bacteria. Nearly a quarter of adults aged 50 and older with diabetes in the U.S. have severe tooth loss. Gum disease can increase blood glucose levels and exacerbate the complications of diabetes.