High blood sugar levels can damage nerves, blood vessels, and organs in the body without you knowing. Keeping your blood sugars, blood pressure and cholesterol levels in a healthy range will help to prevent damage. This handout describes how diabetes can affect your body.


High blood sugars can damage the small blood vessels in the eyes. Damage to blood vessels in the retina (back of the eye) is called retinopathy. Diabetes also raises the risk of cataracts, glaucoma and fluid build-up in the back of the eye, called macular edema. These problems can cause vision loss and lead to blindness.

Some people notice blurry vision, “floaters,” poor night vision, faded colors, or a loss of vision. There may be no sign of changes at first. Keep your eyes healthy by managing your blood sugars and having dilated eye exams at least yearly.


High blood sugar and high blood pressure can damage the small blood vessels in the kidneys. The kidneys start to leak very small proteins called microalbumin. Tests can be done to look for these proteins in your urine and to check how well your kidneys are filtering your blood. Kidney disease is called nephropathy. It can lead to kidney failure and dialysis.

Keep your kidneys healthy by managing your blood sugars and blood pressures. Eat healthy by lowering your sodium intake and including fruits and vegetables.


Neuropathy is damage to the nerves from high blood sugar. It can cause pain, numbness, tingling, and muscle weakness in the hands, legs, and feet. Nerves in the heart, bladder, digestive system, and sexual organs may also be affected.


Heart attack and stroke risk are higher when high blood sugar levels cause damage to the large and small blood vessels. High blood pressure, high cholesterol levels, and smoking increase the risk even more.

Poor Circulation

Loss of blood supply to the legs and feet can lead to problems with healing and infection. Sores that do not heal can lead to amputation.

Oral Health

Gum disease and other mouth problems such as tooth decay, infections, changes in taste, and dry mouth are more likely. High blood sugar levels increase the amount of sugar in your saliva. This allows bacteria to grow. An infection in the mouth can also raise blood sugar levels.

Some people have swollen, tender, or bleeding gums. Others have no signs of gum disease. Keep your mouth healthy by brushing your teeth and gums at least twice per day and floss at least daily. Get cleanings/exams twice a year. Call your dentist with the first signs of problems.

Sexual Problems

Men may experience impotence, ejaculation problems and low testosterone. Women may have problems with arousal, vaginal lubrication, ability to orgasm, and infections.