Why do both hands and lower arms and face go numb?

Answer 1

In Medical Jargon it is called Paresthesias . Mostly it occurs in peripheral areas of body like hands or legs.Peripheral disturbances are the most common cause of paresthesias. "Falling asleep" occurs when the blood supply to a nerve is cut off---a condition called ischemia. Ischemia usually occurs when an artery is compressed as it passes through a tightly flexed joint. Sleeping with the arms above the head or sitting with the legs tightly crossed frequently cause numbness and tingling. Hope this helps

Answer 2

This is usually caused by a pinched nerve. See your doctor.