Diabetes complications

Having diabetes puts you at increased risk of developing other health problems. Diabetes complications include:

  • long-term complications (conditions that develop gradually over time caused by the effect of raised blood glucose levels on the body); and
  • emergency complications (serious conditions that develop quickly as a result of very high or very low blood glucose levels).

Long-term complications of diabetes

Diabetes complications can develop gradually over time due to the effect of raised blood glucose levels on the body. Good control of blood sugar levels can help reduce the risk of diabetes complications and slow down their progression. Treating any additional risk factors, such as high blood pressure, smoking and raised cholesterol levels, can also help reduce the risk of diabetes complications.

Long-term diabetes complications include the following.

  • Cardiovascular problems, including coronary artery disease (which can result in angina and heart attack), stroke and peripheral artery disease (reduced circulation in the legs and feet).
  • Eye complications, including diabetic retinopathy (damage to the small blood vessels in the retina at the back of the eye), cataracts and glaucoma.
  • Diabetic nephropathy (damage to the kidneys), which can result in kidney failure.
  • Diabetic neuropathy, such as damage to the nerves responsible for sensation in the feet and legs (a common complication) and autonomic neuropathy (damage to the nerves that control body functions, which can result in problems with digestion, bladder control and erectile dysfunction).
  • Infections – diabetes increases your risk of infection, such as bacterial and fungal skin infections and gum and tooth infections.
  • Diabetic foot and leg ulcers (which generally result from a combination of poor circulation, nerve damage and an increased likelihood of skin infections). In severe cases, gangrene of the toes and feet can develop.
  • Osteoporosis – a condition that results in weakened bones that are more prone to fractures.
  • Musculoskeletal problems, including carpal tunnel syndrome and frozen shoulder.

Emergency complications of diabetes

The following diabetes complications develop over a short period and can be life-threatening.

Diabetic ketoacidosis

Diabetic ketoacidosis (DKA) occurs when there is not enough insulin available for the body to convert glucose (sugar) into energy, and the body starts breaking down fat for energy. This process releases ketones (a type of toxic chemical) as a waste product.

DKA is characterised by very high blood sugar levels and dehydration, and if the levels of ketones are allowed to keep rising, it can result in coma and death. DKA occurs mainly in people with type 1 diabetes, and can be triggered by having an infection or other illness or not taking your usual dose(s) of insulin.

Hyperosmolar hyperglycaemia

Hyperosmolar hyperglycaemia results from very high blood glucose levels and causes dehydration, confusion, drowsiness and eventual loss of consciousness. It usually affects older people with type 2 diabetes, and is often triggered by an infection or other illness.


Very low blood glucose levels – known as hypoglycaemia – can also affect people with diabetes. Hypoglycaemia can be the result of taking too much insulin or oral hypoglycaemic medicines, not eating enough carbohydrates, drinking alcohol or exercising excessively or for a prolonged period. Severe hypoglycaemia can result in confusion, seizures and loss of consciousness.


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3. MayoClinic.com. Diabetes (updated 31 Jul 2014). http://www.mayoclinic.org/diseases-conditions/diabetes/basics/complications/con-20033091 (accessed Jun 2015).