Numbness and Tingling
Numbness is a loss of sensation in a part of the body, most typically in the hands or feet. Numbness is often accompanied by tingling – a “pins and needles” sensation. While most of the time these symptoms are due to a transient, benign cause, they sometimes indicate a serious medical problem and need to be evaluated by a physician.
A Limb Falls Asleep
By far the most common cause of numbness and tingling occurs when an arm or a leg “falls asleep” after being held in an unusual position for too long.
Most of us have awakened at one time or another with a “dead arm” because we fell asleep with our arm bent beneath our heads. This condition is caused by abnormal pressure on a nerve, and is quickly resolved by moving the affected limb back to a normal position for a few minutes, and letting the nerve recover. This condition is entirely benign and there is no reason to see a doctor if it happens to you. Just try to avoid the offending position from now on.
Repetitive Nerve Damage – Carpal Tunnel Syndrome
In a similar manner, other types of numbness and tingling may be related to localized nerve damage caused by repetitive actions. The most common of these is carpal tunnel syndrome, most commonly seen today in people who spend much of their time on a keyboard. However, this syndrome (and similar syndromes affecting other nerves) can be seen in cyclists, carpenters, meatpackers, and many others.
Treatment includes rest, intermittent breaks, the use of splints, localized treatment with ice, anti-inflammatory agents, physical therapy, and changing the way the repetitive action is performed in order to reduce pressure on the nerve.
On the other hand, numbness and tingling may be related to an underlying neurological disorder, and may not be so benign.
Almost any neurological problem can produce numbness and tingling. Here is a partial list of some of the more prominent neurological causes:
Brain tumors, aneurysms, or AVMs
Spinal disorders (including herniated disc)
Transient ischemic attack
When Should You See A Doctor?
It is not necessary to see a doctor when a limb falls asleep for a readily identifiable cause, and the symptoms go away immediately when you relieve the obvious cause. It also may not be necessary to see a doctor if you have early symptoms of carpal tunnel syndrome, as long as you take steps to relieve the condition and reduce the chronic pressure on your median nerve.
But if you are experiencing numbness and tingling and there is no obvious reversible cause, you need to see your doctor. The list of conditions that can produce these symptoms is quite large; and many of these conditions require treatment not only to relieve the symptoms you are experiencing, but also to prevent much more serious problems from developing.
You should call your doctor right away if you have numbness and tingling which comes and goes for no apparent reason, is gradually worsening, affects both sides of your body, or affects only part of a hand or foot. And if these symptoms come on quite suddenly without any hint of a nerve compression situation, or if they follow a recent head injury, don’t bother calling your doctor or go to an emergency room.