What is type 2 diabetes?

Previously known as non-insulin dependent diabetes or adult onset diabetes

Type 2 diabetes is a condition where your body cannot control its blood glucose (a type of sugar) levels properly. This can lead to a wide range of health problems if not treated.

Key points 

  1. Type 2 diabetes is common, but many people do not know they have it. Check below to find out when you need a screening test.
  2. Most (80%) of type 2 diabetes can be prevented by keeping to a healthy body weight, eating healthier foods and keeping physically active.
  3. Once you have diabetes, you have it for life. But early treatment, including having a healthy lifestyle, can help to reduce damage to your eyes, kidneys, heart, feet and brain.
  4. If you have diabetes, know what your HbA1c, blood pressure and cholesterol are and see your doctor/nurse every 3 months or more for regular check-ups, not just when something is wrong.
  5. Attending a diabetes self-management course, learning as much as you can about diabetes and watching these 10 short videos about diabetes can help you to live well with diabetes.

Diabetes – overview & symptoms Part of a series of 10 short videos about diabetes

What is type 2 diabetes?

Diabetes is a condition where the level of glucose (a type of sugar) in your blood is too high. The amount glucose in your blood is controlled by several different hormones but the main one is insulin.

People with type 2 diabetes do not respond to insulin as well as people without diabetes. You also have some damage to your pancreas, which is the organ that makes insulin.

Type 2 diabetes is a progressive disease, which means it slowly gets worse with time. This is because the cells that produce insulin in your pancreas continue to be damaged or die and your body is less able to make enough insulin to balance the blood glucose.

Can children have type 2 diabetes?

Type 2 diabetes can also occur in children. Most children with diabetes have type 1 diabetes, which is due to severe damage to the pancreas so that not enough insulin is produced. However, children who become overweight can develop type 2 diabetes. Usually there is a family history of diabetes and often the children belong to ethnic groups that are more likely to develop diabetes.

What are the symptoms of type 2 diabetes?

Many people have type 2 diabetes for years without realising because they don’t have symptoms. Others may:

  • feel very thirsty
  • urinate (pee) a lot, especially at night
  • feel very tired
  • have blurred vision
  • have urinary infections or skin infections
  • have itching around your genitals or frequent episodes of thrush
  • find cuts and grazes heal slowly.

How is diabetes diagnosed?

Diabetes is diagnosed using a simple blood test called an HbA1c.

Your doctor will suggest testing for diabetes if you have symptoms that might be due to diabetes. If you are in the high-risk group for type 2 diabetes but don’t have symptoms, your doctor will also request the HbA1c test. Checking for diabetes when you have risk factors, but no symptoms is known as ‘screening’.

Read more about what my HbA1c results mean.

Do I need to be screened for type 2 diabetes?

Are you a man over the age of 45 or a woman over the age of 55?

It is recommended that all men over the age of 45 and all women over the age of 55 are tested for type 2 diabetes, even if you don't have symptoms. Testing for diabetes is part of the routine testing for heart and blood vessel disease, so includes checking your weight and blood pressure, and doing blood tests for cholesterol and fat in your blood. 

Are you a man over the age of 35 or woman over the age of 45 who also:

  • is Māori, Pacific or Indo-Asian
  • has a close family member, such as a parent, brother or sister with diabetes
  • smokes
  • has high blood pressure
  • had diabetes in any pregnancy
  • is overweight (use our BMI calculator)

It is recommended that all men over the age of 35 and all women over the age of 45 with the risk factors above are checked for type 2 diabetes, even if you don't have symptoms. It’s easy to test for diabetes and important to find out so you can take action to prevent damage to your eyes, heart, kidneys and feet.

How can I avoid type 2 diabetes complications?

Diabetes increases the risk of many serious conditions such as poor visionheart disease or stroke, damage to your kidneys (diabetes is the top cause of kidney failure), erectile dysfunction and loss of limbs. The key factor affecting how fast or slowly these complications develop is how well or poorly controlled your blood glucose level is.

The best way to avoid or delay developing diabetes-related health problems is by keeping your blood glucose and blood pressure levels within the healthy range. You can do this by following the advice on managing type 2 diabetes below, which include lifestyle changes and medicines.

Read more about how blood glucose control is measured.

What is the treatment for type 2 diabetes?

The treatment goal for type 2 diabetes is to keep your blood glucose levels within the healthy range as much as possible. Type 2 diabetes is a condition that can be improved by changes in your lifestyle. These changes also help you if you have high blood pressure or too much fat or cholesterol in your bloodstream.

Your doctor will suggest you make changes to your lifestyle first. If these changes work, you may not need to take medication, but even if you do need medicines, you should still try hard to have a healthy lifestyle.

Learn more about treatment for type 2 diabetes.

Support for type 2 diabetes

There are many groups and people keen to share their knowledge and tips for living well with diabetes. Diabetes NZ has branches around the country with a wide range of services, resources, groups and shops. 

Regional diabetes support

Learn more

Diabetes NZ
Diabetes UK

Reviewed by

Dr Jeremy Tuohy is an Obstetrician and Gynaecologist with a special interest in Maternal and Fetal Medicine. Jeremy has been a lecturer at the University of Otago, Clinical leader of Ultrasound and Maternal and Fetal Medicine at Capital and Coast DHB, and has practiced as a private obstetrician. He is currently completing his PhD in Obstetric Medicine at the Liggins Institute, University of Auckland.
Credits: Health Navigator Editorial Team . Reviewed By: Jeremy Tuohy, Researcher & Clinician, University of Auckland Last reviewed: 16 Oct 2019