What Happens

When you have type 2 diabetes, your body still makes insulin. But as time goes on, your pancreas may make less and less insulin, which will make it harder to keep your blood sugar in your target range. If your blood sugar gets too high and stays too high for too long, your risk for other health problems increases. Over time, high blood sugar can damage many parts of your body.

Eyes

High blood sugar levels may cause temporary blurred vision. Blurry vision, floaters, or flashes of light may be a sign of diabetic retinopathy, which can cause severe vision loss. For more help, see:

• Diabetic Retinopathy.
• Vision Aids for Diabetes Care.
• Using Low-Vision Aids at Home(What is a PDF document?).

Feet and skin

You may have less feeling in your feet, which means that you can injure your feet and not know it. Blisters, ingrown toenails, small cuts, or other problems that may seem minor can quickly become more serious. If you develop serious infections or bone and joint deformities, you may need surgery (even amputation) to treat those problems. Common infections can quickly become more serious when you have diabetes. To learn more, see:

Diabetes: Taking Care of Your Feet.

And for more information about foot and skin care, see:

• Checklist for Daily Foot Exams.
• Care of Your Skin When You Have Diabetes.

Heart and blood vessels

High blood sugar damages the lining of blood vessels. This can lead to stroke, heart attack, or peripheral arterial disease. Erection problems can be an early warning sign of blood vessel disease and may mean a higher risk of heart disease. For more information, see the topics:

• Stroke.
• Heart Attack and Unstable Angina.
• Peripheral Arterial Disease.

Nerves

High blood sugar levels can damage nerves throughout your body. This damage is called diabetic neuropathy. There are three kinds of diabetic neuropathy:

• Diabetic peripheral neuropathy. This is damage to the nerves that sense pain, touch, hot, and cold. This type of nerve damage can lead to a deformity called Charcot foot. It can also lead to other problems that may require amputation.
• Autonomic neuropathy. This is damage to nerves that control things like your heartbeat, blood pressure, sweating, digestion, urination, and sexual function.
• Focal neuropathy. Most of the time, this affects just one nerve, usually in the wrist, thigh, or foot. It may also affect the nerves of your back and chest and those that control your eye muscles.

To learn more, see the topic Diabetic Neuropathy.

Kidneys

The kidneys have many tiny blood vessels that filter waste from your blood. High blood sugar can destroy these blood vessels. You won't have any symptoms of kidney damage until the problem is severe. Then you may notice swelling in your feet or legs or all over your body. To learn more, see the topic Diabetic Nephropathy.

Hearing

High blood sugar can damage the small blood vessels and nerves in the ear, causing hearing loss.

Teeth

Gum disease can make it harder to keep blood sugar in a target range. And high blood sugar can cause gum disease, loss of teeth, and healing problems in the mouth. For more information, see:

• Care of Your Teeth and Gums When You Have Diabetes.

Mental health

Type 2 diabetes can raise your risk of depression. It may be caused by the stress of dealing with diabetes or by the effects that diabetes has on your body.

Being depressed can make it hard to eat healthy foods and to find the motivation to exercise. All of these things lead to higher blood sugar. By getting help for depression, you'll feel better and may find it easier to stay motivated. For help, see:

• Interactive Tool: Are You Depressed?