What is pre-diabetes?

Pre-diabetes is when blood glucose levels are higher than normal but not high enough to be called diabetes.

If you have pre-diabetes, you are at 10 to 20 times greater risk of going on to develop type 2 diabetes. If you have been told you have pre-diabetes, it is important to make lasting changes to your lifestyle, including healthy eating, exercising and losing weight, to prevent type 2 diabetes and its complications.

What are the symptoms of pre-diabetes?

There are normally no symptoms of pre-diabetes — most people find out they have it if their doctor orders a blood test. This might happen because they are at risk of pre-diabetes (see below).

See your doctor if you have any signs that your pre-diabetes has moved on to type 2 diabetes, including:

• being more thirsty
• urinating (weeing) a lot
• feeling very tired
• blurred vision

Who is at risk of pre-diabetes?

The risk factors for pre-diabetes are the same as those for type 2 diabetes. They include:

• being overweight, especially if your waist measures more than 94cm for men and more than 80cm for women
• having an inactive lifestyle
• having low HDL (good) cholesterol and high triglycerides
• having high blood pressure
• having a family history of type 2 diabetes or heart disease
• having gestational diabetes during pregnancy
• having polycystic ovary syndrome
• being Aboriginal and Torres Strait Islander or from the Pacific Islands, Māori or from Asia (including the Indian sub-continent)

How is pre-diabetes diagnosed?

There are typically no symptoms for pre-diabetes. If your doctor notices that your blood sugar levels are raised, they may send you for more tests to diagnose whether you have pre-diabetes.

If you have pre-diabetes, you have either one or both of these conditions:

• impaired glucose tolerance — your blood glucose level is above normal but not high enough to be called diabetes
• impaired fasting glucose — your fasting blood glucose level is above normal but not high enough to be diagnosed as diabetes.

Both of these pre-diabetes conditions are confirmed through an oral glucose tolerance test after a fasting blood glucose level is high. For a glucose tolerance test you will need to fast (not eat for 8 hours) and then drink a sugary drink. A blood test is taken after 1 hour and then 2 hours later to measure your blood glucose.

Can pre-diabetes be managed?

If you have pre-diabetes, this does not mean you will necessarily develop type 2 diabetes. Although 1 in 3 people with pre-diabetes will develop type 2 diabetes, eating well and exercise can prevent this in more than half of high-risk cases.

Pre-diabetes is usually managed by making the same healthy lifestyle changes you should make if you had type 2 diabetes. These include healthy eating, regular physical activity and, if necessary, losing weight.

As pre-diabetes also increases the risk of heart disease, it is important to control your blood pressure, cholesterol and triglyceride levels and to quit smoking.

Having an annual health check, including screening for type 2 diabetes, is also important.