Any time you remain still for a long period, particularly if you're leaning on your arm or sitting cross-legged, you are bound to develop a pins-and-needles sensation in one or more limbs. This feeling results from temporary nerve compression and diminished blood flow, and it passes as soon as you move around a bit.
Many medical conditions, however, cause a persistent tingling sensation — usually in the hands, arms, feet, or legs — that is unrelated to posture and unrelieved by movement. While several of these conditions originate in the peripheral nervous system (the network of nerves branching out from the spinal cord to the extremities), others are based primarily in different parts of the body. In general, persistent tingling is a troubling symptom that requires a thorough medical workup.
Causes of tingling sensations
Carpal tunnel syndrome
One-sided weakening or paralysis of the face, known as Bell's palsy, is caused by compression or inflammation of one of the facial nerves and often produces pain or tingling in the affected area. The condition usually resolves itself, but it may persist for months.
This condition, characterized by numbness and tingling in the fingers and pain in the wrist, is the result of pressure on the median nerve, which passes through the wrist and carries sensations to the hand and fingers. An injury or arthritis can give rise to the syndrome, but more often it results from heavy use of the hand and wrist.
Peripheral nerve damage is one of the most common complications of diabetes. The mechanism of the nerve damage is unclear, but poorly controlled blood-glucose levels appear to play a role.
Herpes viruses are never eradicated; instead, they take up residence in nerve cells and can be reactivated, causing repeated outbreaks of painful blisters along the skin overlying the nerve path. A tingling sensation is often the first symptom.
This chronic, progressive condition appears to be an autoimmune disease, in which the immune system produces antibodies to attack the fatty sheath that coats the nerves. Symptom patterns vary widely, but a pins-and-needles sensation may develop in any part of the body during flare ups.
Deficiency of vitamin B12, caused by the stomach's failure to secrete a substance necessary for B12 absorption, underlies this blood disorder. Besides weakness, pallor, and fatigue, symptoms include numbness and prickling in the extremities.
This disorder, in which spasms in the smallest arteries of the hands result in decreased hand circulation, causes cold, numbness, and tingling in the fingers.
Spinal cord disorders
Compression of part of the spinal cord or one of the spinal disks (pieces of cartilage that separate the vertebrae) can cause tingling and shooting pains in the buttock and back of the leg. In some cases tumors in or near the spinal column cause these symptoms.
A stroke, which is an interruption of the blood supply to part of the brain, produces a variety of symptoms, including a severe headache, loss of speech, dizziness, numbness, tingling, loss of sensation, or paralysis on one side of the body Transient ischemic attacks or mini-strokes, with milder symptoms that pass quickly, often precede strokes.
Overexposure to several toxic substances, including lead, alcohol, tobacco, and vitamins A and B6, can damage the nerves and cause numbness and tingling. This type of nerve damage is often permanent.
Advice about tingling sensations
- If you develop unexplained tingling sensations, particularly with other symptoms such as weakness and fatigue, see your doctor at once.
- Unless your doctor has determined that you have a specific vitamin deficiency, avoid vitamin supplements, especially high-doses of vitamins A and B6.