What Causes Numbness and Tingling?

Numbness and tingling in the body can be a sign of a much more serious disease. The sensation, or lack thereof, is most commonly associated with a loss in circulation, such as a foot going to sleep. Depending on the location and severity of the numbness, it may indicate a potentially life-threatening condition. Typically, problems with tingling or numbness can indicate one of several conditions: multiple sclerosis, poor circulation or a pinched nerve. If either sensation persists for a prolonged period, medical attention should be sought as soon as possible.

Multiple sclerosis — one underlying cause of numbness and tingling — occurs when myelins, the fatty sheaths around neurons, are damaged. The myelin sheaths act as an insulator and ensure the smooth transmission of electrical impulses. A neuron with a damaged myelin is comparable to an electrical wire with frayed insulation; prone to short circuits.

In those with multiple sclerosis, the nerves stop transmitting impulses as efficiently. The damage to myelin comes from inflammation caused by the body's own immune system. Sensations of numbness and tingling indicative of this condition can be felt especially in the arms and legs.

If the circulatory system is incapable of sending blood to the extremities, numbness and tingling can result. Without an adequate blood supply, the nerves cannot send information to the brain. Poor circulation can be caused by a buildup of fatty plaque in the arteries, poor nutrition, or a blood clot. Without proper nutrition, capillaries can break down, preventing blood from making a complete trip through the body. Other causes of poor circulation include a weakening heart muscle due to aging.

A pinched nerve can also cause numbness and tingling. Pressure on the nerve, such as from carpal tunnel syndrome in the wrists or a herniated disk in the spine, prevents electrical impulses from traveling along the nerve. Diagnosis of this condition is based upon information provided about the severity and location of the symptoms. An X-ray may also be used to diagnose carpal tunnel syndrome or possible hairline fractures.

Staying in one position for prolonged periods, as when sitting at a computer, can cause numbness and tingling because the muscles are inactive. Periodic stretching and walking breaks keep the body's circulation active. Carpal tunnel syndrome can also be prevented by taking breaks from prolonged typing. Another way to prevent these symptoms is eating a diet high in fruits and vegetables, and low in cholesterol. Regular physical checkups are also beneficial.