Hypoglycaemia and Hyperglycaemia in Diabetes

What are hypoglycaemia and hyperglycaemia, and how are they related to diabetes?

You’ve probably heard of both hypoglycaemia and hyperglycaemia—but what are they, and what on earth do they have to do with diabetes?

Let’s break it down​

First, let’s get the definitions sorted. Hypoglycaemia refers to a drop in blood glucose (sugar) levels, while Hyperglycaemia happens when someone has too much glucose in their blood.

What happens when someone is hypoglycaemic?

A person may experience hypoglycaemia, also called a ‘hypo’, when their blood glucose levels fall below 4mmol/L. Symptoms may include lightheadedness, shaking, weakness, dizziness, headaches, mood changes, sweating, and becoming very pale or hungry.

Hypoglycaemia can be caused by too much insulin or oral glucose-lowering medications, missing a meal, an inadequate intake of carbohydrate-containing foods, drinking alcohol, or strenuous physical activity.


If blood glucose levels continue to fall, they may experience behavioural changes, confusion, slurred speech, seizures, or lose consciousness.

Anyone with Type 1 diabetes must work with their healthcare professional to recognise what a hypoglycaemic event feels like for them and learn how to treat it.

What happens when someone is hyperglycaemic?

Normal blood sugar levels are between 4 – 8mmol/L. Hyperglycaemia occurs when there is too much glucose in the blood, and the blood sugar readings are above 8mmol/L.

Causes include eating too many carbohydrates at once, eating too many high glycaemic index foods, sickness, stress, not taking enough insulin or diabetes tablets, and forgetting to take your diabetes and other medications.

Many people don’t experience hyperglycaemia symptoms until their blood glucose levels are very high. Common symptoms include excessive thirst, frequent visits to the bathroom, weight loss, recurring infections, and feeling fatigued.

Having hyperglycaemia for long periods can lead to organ and tissue damage, particularly in the eyes, hands and feet.

The best way to avoid hyperglycaemia is to work with your dietitian, diabetes educator, and doctor. They will help you achieve a balanced approach to effectively managing your blood sugar levels through diet, exercise and using appropriate medications as required.

It’s important to remember that one size does not fit all. You’ll need to tailor your diabetes management through the ups and downs of life.

Got questions? We can help.

Call us on 0423 206 939 to make an appointment with one of our accredited practising dietitians.