Type 1 diabetes (T1D) is an autoimmune disease in which a person’s pancreas stops producing insulin, a hormone people need to get energy from food. T1D strikes both children and adults at any age and suddenly. Its onset has nothing to do with diet or lifestyle. Though T1D’s causes are not yet entirely understood, scientists believe that both genetic factors and environmental triggers play a role. There is currently nothing you can do to prevent it, and there is no cure.