Some people believe that paresthesia — the heavy, dull, tingling, burning or “weird” pins and needles feeling when your foot falls asleep — is caused by not enough blood circulating to your foot. In reality, though, your foot falling asleep has more to do with your nerves.
Nerves are like tiny wires that run throughout your body. Like the electric wires throughout your house that carry electricity to outlets, your nerves carry messages back and forth between the many parts of your body and your brain.
If you sit on your foot long enough, you compress the nerves in that area. Of course, this can happen to other parts of your body, too. People might experience legs, arms, and hands that fall asleep from time to time.
When you compress the nerves in a certain area, communication from that part of the body to the brain is disrupted temporarily. As a result, that part of your body doesn’t feel anything because it’s not communicating with your brain.
If you also happen to be compressing arteries in that area, blood flow to your nerves may be reduced, too. This can contribute to miscommunication with the brain.
When you change position, the nerves begin to return to normal and start communicating again. While those connections with the brain are being established again, you feel some weird sensations. They usually don’t hurt, though, and they don’t last very long.
Everyone experiences these feelings from time to time, and they’re completely normal. They don’t hurt your body, but they sure can feel really strange for a short time until your brain and your body start “talking” again!