What are the long term effects of diabetes?

Many problems: Untreated or uncontrolled diabetes can lead to kidney disease/failure, retinopathy and possible blindness, impotence (erectile dysfunction), gastroparesis (severe stomach pain and vomitting due to inadequate emptying), foot ulcers and risk of amputation of toes or legs, neuropathy (pins-and-needles sensation mostly in arms & legs), heart disease and possible heart attack & stroke, infection, etc.

poorly controlled..: Then suffer with eye disease-blindness risk; nerve disease- limb ulcers, infections -amputations; kidney disease-dialsis; heart attacks, strokes. But if well controlled can markedly reduce risk of all of these, and have normal life, no complications, normal life span.