If there is a lot of glucose in the blood, the pancreas makes insulin. If there is not much glucose in the blood, it slows production of insulin. When it is working properly, the pancreas keeps the amount of glucose in the blood at an ideal level. In Type 1 diabetes, the body's immune system mistakenly destroys the cells in the pancreas that produce insulin. These cells are known as beta cells.
Beta cells occur in clusters called islets, so they are also known as islet cells.
In fact, beta cells make up most of islets. Experts aren't sure why the body destroys its own cells, but diabetes is not the only evidence that it happens. Other diseases, such as lupus, hyperthyroidism, hypothyroidism, and multiple sclerosis, are also caused by the body destroying its own cells. Heredity Type 1 diabetes often runs in families. Children of parents with this condition are more likely to develop the disease than children whose parents did not have it.