Type 2 Diabetes Complications, Causes, and Prevention

Type 2 diabetes is a chronic health condition characterized by high blood glucose (sugar) levels. It is known to cause inflammation throughout the body, affecting several body systems. Many major organs, including the heart, blood vessels, nerves, eyes, and kidneys can be affected. 

Additionally, risk factors for type 2 diabetes are also risk factors for other serious conditions. The longer you’ve had diabetes, the higher your risk for developing complications. Managing your diabetes and keeping blood glucose levels within recommended ranges can help decrease your risk for several diabetes complications.


People with diabetes are twice as likely to develop heart disease or a stroke compared to people without diabetes. Over time, uncontrolled blood glucose levels can damage your blood vessels. Heart disease, also known as cardiovascular disease, and related blood vessel diseases encompass several different health conditions. 

Diabetes can also increase your low-density lipoprotein (LDL) cholesterol, considered the “bad” cholesterol. Too much of this type of cholesterol can cause your arteries to stiffen and become narrow due to fatty plaque buildup, increasing your risk of a heart attack or stroke. This is called atherosclerosis.

When this plaque builds up in the walls of the arteries that supply blood to the heart, it is called coronary artery disease.

Many people with type 2 diabetes have high blood pressure (hypertension). High blood pressure not only increases your risk for heart attack and stroke, but it can also raise your risk of eye and kidney disease.

Taking any medications your healthcare provider has prescribed and following other lifestyle recommendations can keep your blood pressure under control.

Strokes often occur when a blood clot forms, blocking a blood vessel in the brain, depriving it of sufficient blood flow. This leaves the brain without enough oxygen to function properly, and some of the brain tissue becomes damaged.

Warning signs of a stroke include weakness or numbness on one side of the body, sudden confusion, trouble talking, dizziness or loss of balance, vision problems, or a severe headache.

Strokes require immediate medical attention to help remove the blood clot and restore blood flow to the brain. The specific treatment depends on the severity of the stroke but may include medications and surgery, followed by rehabilitation such as physical, occupational, or speech therapy.

A heart attack occurs when a blood clot decreases blood flow to a part of the heart. If blood flow in an artery is stopped completely, the part of the heart muscle that was receiving blood from that artery begins to die. 

Symptoms of a heart attack include chest pain, discomfort, tightness, or pressure, feelings of indigestion or heartburn, nausea, vomiting, shortness of breath, sweating, fatigue, light-headedness, or discomfort in one or both of your arms, back, jaw, neck, or upper abdomen.

A heart attack requires immediate medical attention in order to improve blood flow to the heart. Your healthcare provider may recommend different medications and lifestyle changes according to how much damage your heart has sustained, as well as how severe the heart disease was that caused the heart attack.

Heart failure is when the heart doesn’t pump blood well enough to meet the body’s needs. It can occur as a result of a heart attack or due to progressive damage to the heart muscle over time.

Heart failure symptoms include shortness of breath, weakness and fatigue (which may limit your activity), coughing, confusion, and swelling in your hands, feet, legs, or abdomen.

Depending on your symptoms and risk factors, your doctor may do tests to monitor for heart failure. The condition is treated with lifestyle changes, medications, and sometimes devices or surgery.

Your risk of heart and blood vessel disease is increased if you have high blood glucose levels, high cholesterol, if you smoke, or are overweight. Changing your lifestyle and adopting healthier habits can help reduce your risk of developing heart and blood vessel problems.

This includes managing your blood glucose, blood pressure, and cholesterol levels, maintaining a healthy weight, eating a heart-healthy diet, such as the DASH (Dietary Approaches to Stop Hypertension) diet or Mediterranean diet (including whole grains; fruits and vegetables; beans, nuts, and seeds; moderate amounts of dairy, eggs, poultry, and fish; and occasional red meat), getting regular physical activity, and quitting smoking if you smoke.

Diabetes is the leading cause of kidney disease. Diabetic nephropathy can cause permanent decreased kidney function and leads to chronic kidney disease. 

The kidneys work to filter waste products from our blood. High blood glucose levels make the kidneys filter too much blood, putting strain on the kidneys. If this increased demand continues over time, protein may be lost in the urine.

Eventually, the kidneys can lose their ability to properly filter the blood, leading to waste buildup in the blood. If your kidneys have extensive damage, it can lead to end-stage renal disease, and you may need dialysis or a kidney transplant. 

Simple urine tests like the urine albumin-to-creatinine ratio (UACR) test can reveal early signs of chronic kidney disease or kidney damage, so testing is important to assessing your risk. The sooner you catch any signs of damage, the more you can do to slow further kidney damage and prevent or delay kidney failure. Keeping your blood glucose levels and blood pressure under control, for example, can help.

Diabetic retinopathy, or eye disease, can cause vision loss and blindness. High blood glucose levels can damage your retina, leading to conditions such as cataracts and glaucoma and damage to the retina’s blood vessels, potentially leading to blindness.

If you have diabetes, it’s recommended to get a dilated eye exam each year. This is because diabetic retinopathy may not have any early symptoms, but detecting it through an annual eye exam can help you take action to protect your eyes. Keeping your blood glucose levels under control can also help prevent or delay vision problems.

Diabetes can decrease the ability of the skin to heal itself, due to an impaired immune response. In people with diabetes, wound healing is of special concern in the feet, due to the increased risk of nerve damage and poor circulation to the feet.

It’s important for people with diabetes to perform daily self foot exams for cuts or wounds. Even minor cuts and scratches on the feet that go unnoticed or are not properly cared for can worsen and develop into a foot ulcer.

Diabetic foot ulcers are lingering wounds that don’t heal well and are more likely to become infected. They are a leading cause of lower limb amputations and disability in people with diabetes.

Other measures you can take to prevent foot ulcers, as well as to help with wound healing in general, are to wear appropriate footwear, get regular foot exams by your healthcare professional, promptly treat and care for any cuts or wounds on your skin, and manage your blood glucose levels.

Peripheral neuropathy is the most common form of neuropathy (nerve damage) in people with diabetes. It generally affects the feet and legs but sometimes affects the hands and arms. Oftentimes symptoms are felt as tingling and numbness or increased sensitivity and pain in the extremities. 

Peripheral neuropathy increases the risk of foot problems such as blisters, sores, foot ulcers, and changes in the shape of your feet and toes. You may have a loss of balance, increasing your risk of being injured due to falling. Some people with peripheral neuropathy experience grief, anxiety, and depression due to chronic pain. 

Your healthcare provider will check for peripheral neuropathy by examining your feet for signs of problems and testing the blood flow and sensation in your feet. If you have peripheral neuropathy, your provider may prescribe a medication to treat the pain or recommend physical therapy to improve balance.

Many different types of neuropathies affect people with diabetes. Below are other types of neuropathy that might occur if you have diabetes.

Autonomic neuropathy is when the nerves that control your internal organs are damaged. This can bring about issues with your heart rate, blood pressure, digestive system, bladder, sex organs, sweat glands, and eyes. It can also cause you to be unaware of low blood glucose levels.

Your healthcare provider will check for various types of autonomic nerve damage by performing different tests and exams, such as checking your heart rate and blood pressure. Treatment for autonomic neuropathy will vary depending on which internal organs and systems are affected.

Mononeuropathy, or focal neuropathy, is a less common form of neuropathy that is usually the result of damage to a single nerve. It most often occurs in the hands, legs, head, or torso. The most common type of focal neuropathy is an entrapment (a trapped nerve) called carpal tunnel syndrome. 

Your healthcare provider will check for focal neuropathies by asking about your symptoms and performing tests to check your nerves and muscles. Treatment for focal neuropathies might include medications to reduce inflammation, wearing a splint or brace to decrease pressure on the nerve, or surgery.

Proximal neuropathy is a rare and disabling type of nerve damage that occurs in the hip, buttocks, or thigh. Usually, only one side of your body is affected. In rare cases, it can spread to both sides. Symptoms include pain, weakness, and/or loss of reflexes in the hip, buttock, or thigh, or legs, as well as muscle wasting or weight loss. 

Treatment may include medication for pain, physical therapy to improve strength or occupational therapy to help with daily activities. Symptoms tend to get worse at first, then slowly improve over time, usually months or years.

People with diabetes are prone to conditions of the skin, such as bacterial infections, fungal infections, itching, discolored skin patches, rashes, diabetic blisters, and other bumps on the skin. Some of these conditions are harmless and don’t require any treatment, while others are more serious and require medical attention.

Preventing these conditions includes taking good care of your skin, such as keeping it clean, avoiding very hot showers or baths, using moisturizing soaps and lotions (don’t put lotion between the toes), and promptly treating any cuts or scratches.

It is a good idea to visit with your healthcare provider or a dermatologist if you have any concerns about your skin, or if you are unable to resolve a skin problem on your own.

People with diabetes are at increased risk for periodontal (gum) disease, which can lead to mouth pain, problems chewing, lingering bad breath, and tooth loss.

Other possible oral health problems caused by diabetes include dry mouth, leading to soreness, ulcers, infections, tooth decay, and thrush. Because people with diabetes have a decreased immune response, this can make the healing process slower than usual.

If you have diabetes it’s important to get routine dental checkups, as well as inspect your own mouth on a regular basis for any signs of periodontal disease. You can also help prevent oral health problems by brushing your teeth twice a day and flossing daily.

Treatment for oral health problems varies depending on the underlying issue but might include a deep oral cleaning, medications, mouth rinses, or surgery.

People with diabetes have a twofold to threefold increased risk of having depression compared to people without diabetes. Experts are unclear of the exact connection between diabetes and depression, however, factors include the high demands of managing diabetes, especially if you take insulin, have poor glycemic control, or have other diabetes complications. 

Signs of depression include feelings of sadness, loneliness, or hopelessness, a loss of interest in things you once enjoyed, changes in appetite or sleeping habits, or even physical symptoms such as pains, headaches, cramps, or digestive problems.

Seeking and obtaining treatment for depression is important for your mental health, and may help improve your diabetes management as well.

Many complications of diabetes can be prevented or delayed by properly managing your diabetes. This includes:

  • Checking your blood glucose regularly and keeping it within recommended ranges
  • Eating a healthy, balanced diet
  • Participating in regular physical activity
  • Making sure your cholesterol levels are normal
  • Maintaining a healthy weight
  • Getting regular health checkups
  • Taking any medications your healthcare provider has prescribed
  • Not smoking or quitting smoking

If you or your healthcare provider thinks there is a problem, a conversation about an action plan is in order. This may lead to specific questions regarding your symptoms or certain exams, tests, or procedures. 

The good news is that with attention to diabetes management, many complications can be prevented, delayed, identified early, and/or successfully treated. Some diabetes complications require more care and treatment than others. 

It’s important to communicate with your healthcare provider concerning your diagnosis and treatment and follow any recommendations set out in your care plan.

Your primary care health professional may refer you to a diabetes specialist, such as an endocrinologist, to better manage your condition. You may be referred to other specialists depending on the complication, such as a podiatrist, ophthalmologist, nephrologist, or dermatologist.

Diabetes can be an overwhelming condition, especially when faced with all the possible symptoms that could occur. Not everyone with diabetes goes on to develop severe or chronic complications. Try to take one day at a time and focus on what you can do that day to manage your diabetes successfully. It’s never too late to start working towards better health.

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