Hyperglycemia, or high blood glucose levels, can lead to several histological changes in various tissues. Persistent hyperglycemia can cause damage to blood vessels, leading to complications such as microangiopathy and macroangiopathy. In the kidneys, hyperglycemia can result in diabetic nephropathy, characterized by thickening of the glomerular basement membrane and mesangial expansion. In the retina, hyperglycemia can cause diabetic retinopathy, marked by the formation of microaneurysms and hemorrhages.
