Diabetes is a disease that involves high blood sugar level — the medical term is "blood glucose." The sugar (glucose) in your blood is your body's key energy source, and it comes from your food.
When you eat, your pancreas releases a hormone called insulin. The job of insulin is to help your body get the sugar out of food, and into your cells, to provide the energy they need to function.
In some cases, your body has problems with insulin. For example:
You can't make any insulin
You can't make enough insulin
Your body can't use the insulin you make properly
When this happens, the sugar stays in your bloodstream, and can't get to your cells, causing a variety of health problems.
The Different Types of Diabetes
Type 1 diabetes: Type 1 diabetes is also known as diabetes mellitus, or juvenile diabetes. Type 1 diabetes is an autoimmune disease. Your immune system attacks and destroys special cells in your pancreas that make insulin, and you produce little or no insulin. Type 1 diabetes is most commonly diagnosed in children and young adults. Type 1 diabetes requires insulin treatment for survival.
Type 2 diabetes: Type 2 diabetes is a type of diabetes where the body is not making or using insulin effectively. In many cases, the pancreas is producing enough insulin, but the body does not respond to the insulin as it's supposed to -- a condition called insulin resistance. Type 2 diabetes can develop at any age, including childhood, but is more common during and after middle-aged. It is also more common in people who are overweight or obese. Type 2 diabetes is considered the most common form of diabetes.
Gestational diabetes: Gestational diabetes is a short-term form of diabetes that is found in some pregnant women. Gestational diabetes usually goes away after childbirth. Women who have gestational diabetes, however, have a greater chance of having or developing Type 2 diabetes.
Latent Autoimmune Diabetes in Adults (LADA) / Type 1.5 Diabetes: While it is not currently recognized as a separate "type" of diabetes, LADA/Type 1.5 diabetes is a form of autoimmune diabetes that most commonly develops in adults. Like Type 1, LADA involves destruction of pancreatic cells that affect your ability to produce insulin. The difference is that LADA often develops slowly and progressively, and is frequently initially diagnosed as Type 2. Unlike Type 2, however, LADA involves elevated antibodies, an usually requires insulin treatment. You can learn more about LADA/Type 1.5 here.