Type 1. This often affects children, but adults can develop it, too. In this form of diabetes, the body’s immune system mistakenly attacks the cells that produce and release insulin. As these cells die, high levels of sugar build up in the blood.

Type 2. diabetes is rising fast in the world, and accounts for 90% to 95% of diabetes cases. A healthy diet and exercise help your body produce and use insulin. Obesity and lack of exercise can damage this process. So, even before you are diagnosed with diabetes, your body cells can become resistant to insulin.
This boosts your risk of heart disease. The pancreas may also stop making enough insulin to overcome the resistance. However, you can prevent and often treat this form of diabetes.

In type 2 diabetes your body probably still makes insulin, but your body’s cells can’t use it well. This is called insulin resistance. It causes high levels of sugar to build up in the bloodstream. As sugar builds up in your blood, you may eventually develop diabetes.

Gestational diabetes: Gestational diabetes occurs in some pregnant women. It can cause complications during labour and delivery. Diabetes that develops in later trimesters usually goes away after the pregnancy ends. However, women who get gestational diabetes are more likely to develop type 2 diabetes later in life.