You have experienced the weird numb sensation in your hands or legs, which we get after staying in one position for a long time, haven’t you? Do you know what it is and what happens in your body when you get it and why?In case whereby the tingling result from staying in an awkward position, the sensation occurs due to the blocking of nerves. The network of nerves that pervades, for example, arms and hands, is connected to the spine via the radial nerve. It stems from the spine and stretches across the shoulder and along the arm. Sleeping with the resting on the arm, lying on it, or draping the arm over a rigid object may cause a constriction of some part of the nerve. The compression blocks signals and affects the hand’s sensory ability. Remember yourself waking up and finding yourself being barely able to move your hand. Blood circulation is also affected: did you see how pale your hand was? When you finally free it, you get a warming sensation as it regains sensitivity and blood refills the thirsty vessels. A vascular spasm (Raynaud’s syndrome) is another common cause of the tingling sensation in fingers. It impedes blood flow in the fingers and makes them feel numb. There are lots of factors contributing to the disorder: cold, physical work, emotional stress, etc. People, whose occupation requires intensive use of fingers (musicians, operators of vibrating devices, etc.), are more likely to develop Raynaud’s syndrome. Some people develop so called Carpal Tunnel Syndrome – a condition resulting from the compression of the median nerve, which is responsible for the work of the thumb, index, and middle finger.