Medical name
Paresthesia, a temporary abnormal sensation caused by nerve compression or disruption
Body & Nervous System
Pins and needles feel like your limb is waking up. What is really happening is compressed nerves restarting their signals after pressure is released.
Pins and needles, medically called paresthesia, happen when a nerve is physically compressed and then that pressure is relieved. When you sit on your foot or lean on your arm for too long, the sustained pressure disrupts the nerve's ability to transmit electrical signals correctly. The nerve goes quiet, which is why the area feels numb. When you shift position and release the pressure, the nerve restarts its electrical activity. During this restart, it fires off signals erratically, producing the tingling, prickling sensation. It is not blood rushing back that causes the feeling. The sensation is the nerve itself rebooting.

Medical name
Paresthesia, a temporary abnormal sensation caused by nerve compression or disruption
What causes numbness
Sustained pressure disrupts the nerve's electrical signaling, silencing it temporarily
What causes the prickling
The nerve restarts and fires erratically during recovery, producing tingling signals
Common myth
People think blood rushing back causes the sensation, but the feeling is actually the nerve, not the vessels
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