Some complications of diabetes may come on rapidly – don’t let them catch you unawares.

Acute complications are medical problems that occur suddenly. In diabetes these can be quickly resolved if you know how to deal with them.

However some acute diabetic complications are emergencies requiring immediate medical attention. Have emergency medical numbers available e.g.

  • Ambulance, South Africa nation-wide: 10177
  • Cell phone emergency: 112

For all complications of diabetes, good blood sugar control is the best prevention, which includes checking your blood sugar levels regularly, as per your doctor’s instructions.

Also know how to recognize the symptoms of each complication described below, and once symptoms are identified, what actions to take. Don’t delay in calling for help in case of a medical emergency.


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Hypoglycemia (low blood sugar/glucose) occurs when your brain and body aren’t getting enough sugar. Taking insulin-releasing pills or insulin puts you at risk because sometimes your medication reduces your blood sugar too much.

Hypoglycaemia is generally defined as when blood sugar drops below 3.9 mmol/L – but check with your doctor for your specific blood sugar target range.

Early hypoglycaemia symptoms may include:

  • Shaking, sweating, rapid heartbeat
  • Vision changes
  • Hunger
  • Headache
  • Sudden moodiness


If you experience any of these symptoms or your blood sugar level is low, have a simple sugar snack e.g. sweets or juice to return your blood sugar to normal and feel better.

Left untreated, early hypoglycaemia symptoms can become severe: these require emergency medical attention, and may include:

  • Unusual behaviour; slurred speech
  • Co-ordination problems, weakness
  • Blurred vision
  • Inattention, confusion
  • Extreme sleepiness/drowsiness
  • Seizures
  • Loss of consciousness

Ask your doctor about glucagon (hormone to raise blood sugar), which people taking insulin carry with them in case of severe hypoglycaemia; it can be used by someone trained to administer it while waiting for emergency services.

More on Hypoglycaemia

Diabetic Ketoacidosis (DKA)

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DKA – a condition caused by inadequate insulin – is a medical emergency usually affecting people with Type 1 diabetes.


DKA is usually (not always) indicated by high blood sugar levels. Without enough insulin, the body can’t burn glucose efficiently. Fat moves from fat cells to the liver and glucose builds up in the bloodstream. The liver makes ketoacids (ketones) from the fat. The result is toxic levels of excess glucose and ketoacids.

The lack of insulin that causes DKA is usually from:

  • Unknown or newly diagnosed type 1 diabetes
  • Missed or inadequate insulin doses
  • Another severe illness e.g. severe infection
  • Steroid medications

Call emergency services immediately if you notice any symptoms of DKA, which may include:

  • Nausea, vomiting
  • Stomach pain
  • Fruity breath – scent of ketoacids
  • Frequent urination
  • Excessive thirst
  • Weakness, fatigue
  • Speech problems, confusion
  • Heavy, deep breathing
  • Unconsciousness

Hyperglycemic Hyperosmolar State (HHS)

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HHS is an uncommon medical emergency associated with very high blood sugars that occurs in people with type 2 diabetes.

Call emergency services immediately if you notice any symptoms of HHS, which may include: excessive urination, dehydration, extreme fatigue, confusion. Seizures and coma may occur. There iss usually just enough insulin available to prevent ketone formation, so ketone levels are normal or slightly elevated.

HHS usually happens to people unaware they have diabetes, or to those diagnosed with diabetes who develop another illness and don’t check their blood sugar or drink enough fluid.

Diabetes Education Online Diabetes Teaching Center at the University of California, San Francisco. Living with diabetes: complications. Link:

NHS. Low blood sugar – hypoglycaemia. 2020.


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