Diabetes mellitus is a metabolic disorder in which either the pancreas fail to produce enough effective insulin hormone or the body cells become resistant to the insulin hormone's effect.

The food you eat is broken down into a sugar called glucose. Glucose levels increase after a meal, but quickly return to normal as body cells remove excess glucose from the bloodstream. A hormone called insulin in the bloodstream helps cells take up glucose and use it as energy. But in some people, either the pancreas cells do not make insulin or cells of the body cannot use the insulin properly. Without insulin, cells are unable to take up glucose. Instead, high levels of glucose builds up in the bloodstream causing Diabetics (where it can cause damage to eyes, nerves, and blood vessels).

There are a number of factors, both genetic and environmental, that may increase a person's risk of developing diabetes. People who have family members with diabetes are at a higher risk for developing the disease. Although diabetes can run in families, inheriting a particular gene mutation does not guarantee that a person will get the disease. They must also have certain environmental factors that trigger diabetes, which include obesity, inactivity, increasing age, and a history of gestational diabetes.