Why are my arms numb when I wake up each morning?

Carpal tunnel . Most common cause is carpal tunnel syndrome which is a pinched or compressed median nerve at the wrist which supplies the thumb, index, middle, and half the fourth finger but can cause the arms to feel numb. When you sleep, the wrists often bend or flex making carpal tunnel syndrome worse. Your doctor can check it out.

Related Questions

Why are my arms numb when I wake up in the morning even though the feeling comes back quickly?

Compression. Most likely you are describing some type of nerve compression while you are sleeping. Changing slightly the postion you sleep in may help, however this is typically a self limiting problem. Read more...