Microvascular Complications of Diabetes

Chronic hyperglycemia injures capillary endothelium, thickens basement membranes, and disrupts normal blood flow through the smallest vessels. The result is a damaging combination of leakage and ischemia: some tissues become edematous because vessels leak, while others lose oxygen because narrowed or damaged capillaries cannot deliver enough blood. The retina, peripheral nerves, and glomeruli are especially vulnerable. Their injury produces diabetic retinopathy, neuropathy, and kidney disease. These complications often progress quietly; a patient may feel well while retinal damage advances or albumin begins leaking into the urine. Blood pressure and lipid control matter because hypertension increases pressure across already-fragile microvessels, while dyslipidemia adds vascular injury. Glycemic control reduces ongoing damage, but it does not reverse a detached retina, restore lost nephrons, or make an insensate foot reliably protective again.