Southern Cross Medical Library

Southern Cross Medical Library

Over 250,000 New Zealanders have been diagnosed with diabetes (diabetes mellitus) and it is estimated another 100,000 have diabetes that has not been diagnosed.

It is a condition that occurs when levels of glucose (sugar) in your blood are too high. If left untreated, diabetes can cause or contribute to serious health issues like coronary heart disease, kidney damage, stroke, circulatory problems, eye damage (including cataracts and glaucoma), miscarriage, cellulitis, vaginal thrush, and oral thrush.

Type 2 diabetes is the most common form of diabetes. In New Zealand, the rate of type 2 diabetes is increasing rapidly and in some regions is considered to have reached epidemic proportions. Māori and Pasifika New Zealanders are more than three times more likely to develop diabetes than most other New Zealanders. Rates of diabetes are also high among Asian New Zealanders.

What is diabetes?

Diabetes is a metabolic disorder, which means a problem with how the body digests and uses energy. Most forms of diabetes are chronic (long-term) conditions, and all are characterised by high levels of glucose in the blood (hyperglycaemia).

During digestion most foods are converted into a sugar called glucose. Glucose is a simple sugar that is the main fuel source for the body. Once food has been converted into glucose, it moves into the bloodstream where it is circulated around the body. It then passes into the body's cells to be used as energy.

For glucose to pass from the bloodstream into the cells, a hormone called insulin is required. Insulin is produced in the pancreas – a large gland that sits behind the stomach. Specialised cells in the pancreas called beta cells normally produce the correct amounts of insulin to move the glucose from the blood into the cells. Insulin production rises and falls throughout the day in response to the body's needs. However, in people with diabetes there is a problem with the production of insulin or with the body's ability to respond to the insulin.

Diabetes symptoms can include excessive urination and thirst, excessive eating or hunger, fatigue, and nausea. Treatment aims to maintain healthy blood glucose levels and to prevent serious health complications.

Types of diabetes

There are three main types of diabetes – type 1, type 2, and gestational – associated with different circumstances.

Type 1 diabetes:

Type 1 diabetes is a life-long variation of diabetes that typically takes hold in childhood or adolescence but may occur in older age groups. It is the result of the body’s immune system destroying the pancreas where insulin is made resulting in the body being unable to produce insulin. Symptoms of type 1 diabetes can appear suddenly. The condition can cause serious health complications over time but can be managed with insulin replacement therapy and lifestyle changes.

Type 2 diabetes:

Type 2 diabetes is a life-long variation of diabetes often associated with being overweight. It is the result of the body not producing enough insulin and/or being unable to respond to insulin. Symptoms of type 2 diabetes develop gradually. The condition can cause serious health complications over time but can be managed with lifestyle changes and medication.

Gestational diabetes:

Gestational diabetes is a variation of diabetes that occurs during pregnancy. It is the result of the mother not being able to produce enough insulin. Gestational diabetes may not present obvious symptoms but may be diagnosed during routine pregnancy screening. The condition can adversely affect the pregnancy and health of the baby but can be managed with diet modification, exercise and, if necessary, medication.

Diabetes can also occur as the result of:

  • certain medications – e.g., prednisone (a corticosteroid medication) and some diuretics (water tablets), which can increase the chances of developing diabetes by reducing the body’s ability to respond to insulin
  • certain medical conditions – e.g., diseases of the pancreas (e.g., chronic pancreatitis) and some disorders of the hormone-producing endocrine glands (e.g., Cushing's syndrome)
  • trauma or surgery – e.g., injury to the pancreas or surgical removal of the pancreas
  • some genetic disorders – e.g., Down's syndrome, Turner's syndrome, and some muscular dystrophies.

Further support and information

It is important for people with diabetes to have broad support from areas such as family, partners, healthcare professionals, and diabetes support groups. Information can be obtained from Diabetes New Zealand – a nationwide, non-governmental, non-profit, membership organisation.

Diabetes New Zealand

Freephone: 0800 DIABETES (0800 342 238) for general inquires and information.

E-mail: [email protected]


Diabetes New Zealand also provides support and information specifically aimed at young New Zealanders. Many of its branches around the country host type 1 diabetes youth support groups (visit the Diabetes New Zealand website for details).

Reviewed: September 2023

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The purpose of the Southern Cross Medical Library is to provide information of a general nature to help you better understand certain medical conditions. Always seek specific medical advice for treatment appropriate to you. This information is not intended to relate specifically to insurance or healthcare services provided by Southern Cross.