When we sit or stand in one position for long, the pressure on a single part of the body causes the neurons to stop sending signals to the brain, which results in the feeling of numbness.
There are many things that can cause body parts go numb. The most serious of these issues to cause numbness include insect or animal bites, radiation therapy, toxins, abnormal levels of vitamin B12 or other vitamins, potassium, calcium, or sodium, carpal tunnel syndrome, injured nerve, herniated disk, diabetes, frostbite, shingles, Raynaud’s phenomenon, transverse myelitis, encephalitis, multiple sclerosis, underactive thyroid, seizures, hardening of the arteries, stroke, or mini stroke.
However, the majority of us feel numbness in our body parts when we fall asleep on our arm, or when we have been sitting or standing in the same position for long, especially if we have been sitting in a cross-legged position. The numbness is often characterized by a tingling sensation. The official name for this numbness and tingling is paresthesia. However, in common parlance we may refer to it as a body limb falling asleep and of feeling pins and needles in the limb.
The reason that this numbness and tingling occurs is due to the nerves running through our bodies. These nerves act as lines of communication between the brain and the other body parts, transmitting commands from the brain and relaying sensory information back to it for processing. When we end up sitting or sleeping on the arm or leg, it end ups reducing the blood circulation to that limb. This also results in a cut off between the communication from the brain to the limb and vice versa. Hence, we don’t feel the limb so to say. Still there are some nerves that start acting haywire and fire neurons everywhere, which results in the tingling feeling in the limb.
The best way to fix the feeling of numbness and tingling is to move the position of the said limb, and hence allowing the neurons to regain the connection to the brain. Once the connection is fixed, the neurons will sent the signals properly to the brain and the feeling of numbness and tingling will disappear over time. It is does not, or the numbness occurs frequently and without the pressure of sitting on that part of the body, it is best to see a doctor.