Numbness is a complete loss of feeling when you touch your skin. It may feel like the part you touch does not belong to you.

Tingling is a pins-and-needles feeling. Almost everyone has had this feeling at some time—for example, when your foot "falls asleep." An occasional, slight tingling that lasts only briefly is not generally cause for concern.

It is not unusual to wake up in the morning with numbness or tingling if you sleep on your hand. This may temporarily cut off blood flow to your hand or put pressure on a nerve. If this is the case, the feeling will come back within a minute or two. See an illustration of skin innervation of the hand.

Overuse of your hands and wrists may lead to conditions such as carpal tunnel syndrome and ulnar tunnel syndrome. Pressure on a nerve (median or ulnar nerve) in the wrist causes tingling, numbness, weakness, or pain in the fingers and hand.

Numbness and tingling are more serious when:

• You have a complete loss of feeling.
• You have symptoms of decreased blood flow, such as pale, white, blue, or cold skin.
• You have muscle weakness not caused by pain.
• Symptoms don't go away.
• Symptoms go away, but keep coming back.