why do limbs fall asleep : The unnerving, separate sensations we feel when a body part "falls asleep" truly result from nerves under pressure.
Scientists, using the arm as an example of a limb that has fallen asleep, explain that the person, most likely, slept on the arm. This sleeping position exerted pressure on the nerves, which squeezed them and, thus, inhibited the messages the nerves carry to the brain and to the rest of the body. If sleeping on the arm also squeezed the blood vessels, oxygen normally carried to the nerves by these vessels never made it to its destination.
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