Microvascular damage. Microvascular ischemia is the change that can occur in certain tissues after they are deprived of oxygen. This process can occur most commonly in diabetics and hypertensives. It affects the eyes (retina), kidneys, brain and other very oxygen dependent tissues. Great question by the way.
Can be significant. In the heart? In the brain? Microvascular simply refers to the tiny blood vessels, ischemia is a lack of oxygen due to insufficient blood flow. Unlike the larger vessels, where plaque is usually the limiting factor in blood flow, microvascular disfunction is usually due to damage or disease.
End organ insult. Micro -small vessels to end organs like kidney skin even heart ischemia causes death or dysfunction.