Diabetes is an epidemic. In the US, diabetes affects more than 18 million, 5 million undiagnosed. This growing global health problem is expected to present one of the 21st century's biggest medical challenges, with a huge increase in worldwide numbers forecast to 200 million from the current 150 million.In type 2 diabetes, either the body does not produce enough insulin, or the cells ignore the insulin, necessary to process sugar, the basic fuel for body cells. Symptoms include excess thirst, passing large amounts of urine, tiredness, weight loss, and feeling generally unwell. Complications can include: increased risk of heart disease, stroke and poor circulation; eye and vision problems; kidney damage; nerve damage; serious foot problems; and impotence.