Numbness in a hand is usually caused by damage, irritation or compression of one of the nerves or a branch of one of the nerves in your arm and wrist.

Diseases affecting the peripheral nerves, such as diabetes, also can cause numbness, although this is often preceded by similar symptoms in your feet.

Rarely, numbness can be caused by problems in your brain or spinal cord, although this is usually accompanied by weakness or loss of function in your arm or hand. Fortunately, numbness by itself is only rarely associated with potentially life-threatening disorders, such as strokes or tumors.

Your doctor will need detailed information about your symptoms to diagnose the cause of your numbness. A variety of tests may be needed to confirm the cause before appropriate treatment can begin.

Possible causes of numbness in one or both of your hands include:

  1. Radiation therapy
  2. Amyloidosis (when substances called amyloid proteins build up in your organs)
  3. Brachial plexus injury (an injury to the network of nerves that conducts signals from the spine to the shoulder, arm and hand)
  4. Carpal tunnel syndrome
  5. Cervical spondylosis (age-related wear and tear affecting the disks in your neck)
  6. Ganglion cyst (noncancerous fluid-filled lumps that most commonly develop along the tendons or joints of your wrists or hands)
  7. Guillain-Barre syndrome (an uncommon disorder in which your body's immune system attacks your nerves)
  9. Lyme disease (a tick-borne illness)
  10. Multiple sclerosis
  11. Paraneoplastic syndromes of the nervous system (a group of rare disorders that develop in some people with cancer)
  12. Peripheral neuropathy (nerve damage that often causes numbness and pain in your hands and feet)
  13. Raynaud's disease (a condition that causes some areas of your body to feel numb and cool in response to cold temperatures or stress)
  14. Side effects of chemotherapy drugs
  15. Sjogren's syndrome (an autoimmune disease that causes dry eyes and dry mouth)
  16. Spinal cord injury
  17. Syphilis
  18. Syringomyelia (the development of a fluid-filled cyst, or syrinx, within your spinal cord)
  19. Type 2 diabetes
  20. Ulnar nerve compression
  21. Vasculitis (an inflammation of your blood vessels)
  22. Vitamin B-12 deficiency

Causes shown here are commonly associated with this symptom. Work with your doctor or other health care professional for an accurate diagnosis.

April 20, 2013