Limb numbness. It will help if you specify whether this is only in 1 limb, only upper or lower limbs, or all limbs. If the numbness/tingling is sudden and in all 4 limbs, then the most likely cause is either hyperventilation or simple anxiety, which may however be severe. Symptoms in 1 limb could be a stroke, nerve injury, or vascular problem. In the upper or lower limbs this could be a spinal nerve problem.