Hypoxia and Medicine

why do our limbs feel stingy (like ant bites) after a period of ischemia?

why do our limbs go numb after a period of restricted blood flow, and why do we feel that sensation after blood flow is restored?

Public Comments

1. Your limbs go numb after restricted blood flow, because red blood cells contain oxygen that your limbs cannot be deprived of for extended periods of time. Most human cells require ample oxygen because of their energy requirements. In the absence of oxygen, cells use less efficient energy-generating pathways (glycolysis rather than Krebs and eventually electron transport) which are insufficient to keep the tissues of your limbs alive. Your sensory nerve cells also require blood flow and as such can sense deprivation of oxygen. When blood flow is restored, your sensory receptors are temporarily overactivated, explaining that "feeling."