Pressure on the arm while sleeping and the phenomenon of tingling occurs, first of all, because the blood flow in the arm does not run smoothly after the pressure, and at the same time, because there is not much blood returning to the heart at night, so the blood supply to the upper limbs is less, which will more easily cause tingling in the arm. On the other hand, if you have frozen shoulder, carpal tunnel syndrome, elbow tunnel syndrome and other pathologies, it will aggravate the pressure on the blood vessels and nerves in the elbow tunnel, thus causing the symptoms of arm numbness to occur more frequently.