People with diabetes must routinely monitor and regulate their blood sugar. No matter how careful you may be, there’s still a possibility that a problem might arise.

There are two types of complications you may experience: acute and chronic. Acute complications require emergency care. Examples include hypoglycemia and ketoacidosis.

If left untreated, these conditions can cause:

  • seizures
  • loss of consciousness
  • death

Chronic complications occur when diabetes isn’t managed properly. Diabetes causes high blood sugar levels. If not controlled well over time, high blood sugar levels can damage various organs, including the:

  • eyes
  • kidneys
  • heart
  • skin

Unmanaged diabetes can also cause nerve damage.

People with diabetes can experience sudden drops in their blood sugar. Skipping a meal or taking too much insulin or other medications that increase insulin levels in the body are common causes. People who are on other diabetes medications that do not increase insulin levels are not at risk for hypoglycemia. Symptoms can include:

  • blurry vision
  • rapid heartbeat
  • headache
  • shaking
  • dizziness

If your blood sugar gets too low, you can experience fainting, seizures, or coma.

This is a complication of diabetes that occurs when your body cannot use sugar, or glucose, as a fuel source because your body has no insulin or not enough insulin. If your cells are starved for energy, your body begins to break down fat. Potentially toxic acids called ketone bodies, which are byproducts of fat breakdown, build up in the body. This can lead to:

  • dehydration
  • abdominal pain
  • breathing problems

Diabetes can damage blood vessels in the eyes and cause various problems. Possible eye conditions may include:




This is when pressure builds up in the eye and restricts blood flow to the retina and optic nerve. Glaucoma causes gradual loss of eyesight. People with diabetes are as likely to develop glaucoma.

Diabetic retinopathy

This is a general term that describes any problems of the retina caused by diabetes. In the earlier stages, capillaries (small blood vessels) in the back of the eye enlarge and form pouches. This can lead to swelling and bleeding that distorts your vision.

It can also advance to the proliferative form. This is where blood vessels of the retina are so damaged that they close off and force new blood vessels to form. These new vessels are weak and bleed. The proliferative form can lead to permanent vision loss.

Macular edema

The macula is the part of your eye that lets you see faces and read. Macular edema is caused by diabetic retinopathy. When capillary walls lose their ability to control the passage of substances between the blood and retina, fluid can leak into the macula of the eye and cause it to swell. This condition causes blurred vision and potential loss of vision. Prompt treatment is often effective and can control vision loss.

High blood sugar levels over time can damage your kidney’s ability to filter waste out of the body. It can also cause substances that are usually not filtered into the urine, such as protein, to be released. You are at higher risk for kidney disease if you also have high blood pressure. Diabetes is the leading cause of kidney disease. If not treated, diabetic kidney disease may lead to the need for dialysis.

Excess sugar in the bloodstream can damage the nerves of the body. This can happen to the nerves that control automatic processes of the body, such as digestion, and can happen in the nerves that control the extremities, such as the feet. This can lead to:

  • tingling
  • numbness
  • pain
  • burning sensations


High blood sugar levels can cause damage to the blood vessels in the body. This can cause problems with circulation and increase the risk of foot problems and other vessel diseases, such as heart attack and stroke.


Long-term complications of diabetes develop gradually. The longer you’ve had diabetes, the higher your risk for complications. Proper preventive care can help you control or avoid many or all of these diabetes complications. The better you are at managing your blood sugar levels, the lower the risk of developing complications, and the better your long-term outlook.