What makes your body parts feel numb when they fall asleep?

Answer 1

Quoting & paraphrasing the source below:

When you sit on or squeeze your arm or leg for a prolonged period of time, "you actually cut off communication from your brain to parts of your body. The pressure squeezes nerve pathways so that the nerves can't transmit electrochemical impulses properly." It also cuts off blood & nutrients to those nerves.

Answer 2

My youngest son has a tendency of doing this all the time when he sleeps...he used to wake up screaming because he'd been sleeping in some weird position and honestly I'm surprised he hasn't done nerve damage. He still sleeps on his hands all the time and I have to check on him constantly.

It's like everyone has said, you cut off the blood and nerve impulses and when you remove the pressure causing it, they start to wake up but as they do, the messages to the brain are all jumbled up, which is why you can't stand up sometimes as your leg buckles from under you. The impulses are not communicating from the leg to the brain and it doesn't know what to do which is why it buckles if you try to move before the "connection is re-established".

Best to just let the area "wake up" (that's what the tingling is...nerves booting up again so to speak) and wait til it's functioning properly to walk on it if it' s your leg. You don't want to fall and twist or break anything.

Answer 3

Decreased oxygen supply to the body, because when you sleep the body does not require oxygen too much .
Next your Basal metabolic tate falls and results in cooling of body,which in turn resuts to lesser oxygen demand. Hence Numbness of body is a natural phenomena. So Enjoy Life And Forget about Numbness.
Take 20 deep breaths while in bed.

Answer 4

It's related to the nervous system. Sometimes when we keep our limb in one position for too long and we press on a certain nerve not knowing about it your limb will fall asleep due to weaknes of the nerve conduction. Many times however our limbs fall asleep due to certain neurological conditions or disorders such as Cervical or Lumbar Radiculopathy (Radiculitis). Herniation of a disk can also contribute to that condition. If your extremities (limbs) fall asleep too often you should seek a professional help in a clinic. There are tests such as Nerve Conduction Velocity Study and MRI of your spine that can show if there is a mild to severe condition involved.

Answer 5

Lack of blood ciruclating to that area. It's being cut off by whatever limb is being suffocated.

Answer 6

you are cutting off the circulation to that area