Type 1 diabetes usually occurs suddenly and shows up by age 20. It is controlled by taking insulin shots and following a balanced diet and exercise plan. Type 2 diabetes is much more common. It usually happens gradually after age 40. You may need more insulin than your body makes, or there may be other reasons why your cells can't get enough glucose.
Some women develop diabetes during pregnancy.
In this case, it may resolve itself after the baby is born. The result of either type of diabetes is high blood sugar, or hyperglycemia. Over time, high blood sugar can damage your heart, kidneys, and blood vessels, leading to serious problems, including blindness, amputations, heart disease, and stroke. We don't know what causes diabetes, and there is no cure. But with proper diet, exercise, and medication you can control it.