paresthesia

Sustained pressure compresses the nerves running through your limbs, blocking the electrical signals that carry sensation to your brain and creating numbness. When you shift position and release the pressure, those compressed nerves 'wake up' with a flood of erratic firing that produces the familiar 'pins and needles' tingling sensation called paresthesia. This temporary phenomenon is harmless and resolves in seconds, but understanding what happens reveals how your peripheral nervous system works and when similar sensations might signal something more serious.