Types of diabetes

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Find out about the two most common types of diabetes: type 1 and type 2 diabetes. Symptoms and causes differ for each.

Key points

  • The most common types of diabetes are type 1 and type 2 diabetes.
  • In type 1 diabetes, the pancreas loses its ability to make insulin.
  • Most cases of type 1 diabetes occur in children or adolescents.
  • In type 2 diabetes, the pancreas still makes insulin however, either the pancreas does not make enough insulin or the body cannot properly use the insulin that is being released.

The most common types of diabetes are type 1 and type 2. However, diabetes can be from other causes, such as pregnancy (gestational diabetes) or cystic fibrosis. For some people, diabetes can occur when they are treated with medicines such as steroids.​​​

Type 1 diabetes

Type 1 diabetes was previously known as insulin-dependent diabetes mellitus (IDDM), juvenile diabetes or childhood diabetes. Only a small proportion of all people with diabetes (5% to 10%) have type 1 diabetes, and most cases occur in children or adolescents. There is no cure for type 1 diabetes, but the condition can be well managed.

What happens in type 1 and type 2 diabetes
 

In type 1 diabetes, the pancreas loses its ability to make insulin. By the time the symptoms of diabetes occur, most of the beta cells in the pancreas have been damaged or destroyed. Nobody knows for certain how long this damage has been happening. It is probably many months or years.

Children with type 1 diabetes cannot use the carbohydrates in the food they eat for energy because their bodies are not producing enough insulin; in order for them to use the sugar for energy, the missing insulin must be replaced.

Insulin is usually given by injection or with the use of a pump. The amount of insulin given must be carefully balanced with how much and what kind of food is being eaten (what the body does naturally in patients without diabetes). To ensure that insulin is being given and used appropriately so that there is not a buildup of sugar in the blood, the amount of sugar in the blood and in the urine must also be measured regularly.

Type 2 diabetes

Type 2 diabetes is the most common form of diabetes.  In the past, almost all people who were diagnosed with type 2 diabetes were (older) adults. As a result, the condition was previously called non-insulin dependent diabetes mellitus (NIDDM), or adult-onset diabetes.

However, type 2 diabetes is now being diagnosed in teenagers and children. This may be related to a higher body weight or increasing obesity.

In type 2 diabetes, the pancreas still makes insulin. However, either the pancreas does not make enough insulin or the body cannot properly use the insulin that is being released (known as insulin resistance). In either case, this causes blood sugar levels to increase, with the body not able to use the sugar that is in the blood.

Some people with type 2 diabetes can manage their diabetes with exercise and a healthy diet, while others will also require oral medication (pills). If these treatments do not work, insulin injections might also be required.

Differences between type 1 and type 2 diabetes

Infographic of the differences between type 1 and type 2 diabetes

Other types of diabetes

Diabetes due to cystic fibrosis

Cystic fibrosis is a condition that can affect several organs, including the pancreas. Over time, the pancreas can lose its ability to make enough insulin. This leads to diabetes.

Diabetes due to medication

Some medications, such as steroids, can cause diabetes. Dexamethasone and prednisone are examples of steroids that can cause diabetes when used for a long period of time. Diabetes due to medication might go away when the medication is stopped; however, this is not always the case.

Last updated: October 17th 2016