The sensation of an arm or leg falling asleep is a common one. If you sit or recline in such a way that you put pressure on a limb, you may sometimes block nerve signals, causing numbness. Once the pressure is removed, the nerve "wakes up" with a prolonged tingling sensation. However, experiencing these symptoms without an obvious source of pressure may indicate nerve damage or other medical conditions that could be life threatening.
Carpal Tunnel Syndrome and Ergonomics
One common cause of numbness and tingling in the hands is carpal tunnel syndrome. Carpal tunnel syndrome occurs when you put constant pressure on the median nerve in the wrist, explains MedlinePlus. This may be from spending too much time performing repetitive motions and from using computer keyboards. Likewise, a poorly adjusted office chair might put pressure on nerves in the legs, causing numbness or pain in the feet. Sometimes, switching to ergonomically appropriate equipment and taking regular breaks may relieve symptoms, but extreme cases may require cortisone shots or even surgery to correct.
Diabetic Neuropathy
An excess of glucose in your blood may lead to damage of your organs and nerves. Over time, uncontrolled diabetes may cause nerves in the extremities to stop functioning correctly, reducing the signals they transmit and sometimes causing phantom pains as well. If you have diabetes, you should take all necessary precautions to keep your blood glucose within healthy levels, and you should report any numbness or tingling sensations to your doctor immediately.
Nerve Damage or Blockage
Damage to any nerve in your body may create a sensation of numbness or tingling in the affected area. Bilateral tingling and numbness in the legs may be the sign of a nerve blockage or pressure on the spinal column, such as that caused by a herniated disk. A condition that affects the spinal cord closer to the brain may create such sensations anywhere in the body, depending on the nature of the damage.
Toxins
Many different types of toxins may affect your body's ability to transmit nerve impulses. Long-term exposure to lead or mercury inhibits normal nerve function, as does abuse of alcohol, tobacco or drugs. These symptoms usually build up over time and may affect any area of your body.
Stroke or Neurological Events
A sudden onset of weakness, numbness or tingling on one side of the body may indicate a stroke or sudden neurological event. If the symptoms include difficulty speaking, hearing or seeing, or a loss of consciousness occurs, you should call 911 immediately. Quick medical attention after a stroke can mean the difference between a full recovery and a much longer road back to health.
