retinopathy - damage to small blood vessels in the eyes
neuropathy - nerve damage that can happen anywhere 9n
stroke - caused by damage to the larger blood vessels
heart disease
those are the main ones I am aware of......
the stroke and heart attack are obviously major but could be assumed to only happen after many years of poor control, but in reality may happen eventually after a lifetime of diabetes..............
I suppose everyone is different but I would expect other complications to manifest before that, giving a good indication that you need to pull the finger out........