Numbness is the absence of feeling and is often accompanied by a tingling sensation. It can occur in any area of the body, but most of the time this sensation is felt in the arms, hands, fingers, legs and feet.
There are many possible causes of numbness. Sometimes the sensation is caused by medical conditions like carpal tunnel syndrome, diabetes, migraines, seizures, strokes and “mini-strokes,” an underactive thyroid gland and multiple sclerosis. Nerve injuries also cause numbness. A lower back injury can cause numbness and tingling in the back of the legs, and a neck injury can produce the sensation anywhere in the arms and hands. Nerve damage due to the effects of lead, alcohol or tobacco also triggers the sensation.
Other causes include pressure from a herniated disc; pressure on the spinal nerves caused by enlarged blood vessels, scar tissue, infection and/or tumors; a lack of blood supply to the affected area; imbalances in calcium, potassium or sodium levels in the body; a lack of vitamins in the body; or simply remaining in the same position for a prolonged period of time.