The complications of diabetes can be divided into three major groups. Firstly microvascular which comprises both retinopathy and nephropathy. The second group is neurological, which may have a microvascular component as well as disturbed neural function. The third, macrovascular, includes diseases of the large vessels supplying the legs (lower extremity arterial disease), the heart (coronary heart (or artery) disease) and the brain (cerebrovascular disease).