Diabetes is a common disease, with about 422 million people worldwide living with the condition as of 2014. It is estimated that by 2040, this number will have increased to 629 million people. The most common form of diabetes is type 2 diabetes, which is often associated with obesity and a sedentary lifestyle. Type 1 diabetes, which is an autoimmune disease, is less common but can occur at any age. Gestational diabetes, which occurs during pregnancy, is also relatively common. In the United States, it is estimated that about 10% of the population has diabetes.