Definition of Numbness and tingling:

Numbness and tingling are abnormal sensations that can occur anywhere in your body, but are often felt in your hands, feet, arms, or legs.

Common Causes:

There are many possible causes:

• Remaining in the same seated or standing position for a long time
• Injury to a nerve -- for example, a neck injury may cause you to feel numbness anywhere along your arm or hand, while a low back injury can cause numbness or tingling down the back of your leg
• Pressure on the spinal nerves such as that due to a herniated disk
• Lack of blood supply to an area -- for example, plaque buildup from atherosclerosis in the legs can cause pain, numbness, and tingling while walking (this is called vascular claudication)
• Other medical conditions, including:
  • Carpal tunnel syndrome
  • Diabetes
  • Migraines
  • Multiple sclerosis
  • Seizures
  • Stroke
  • Transient ischemic attack (TIA)
  • Underactive thyroid
• Abnormal levels of calcium, potassium, or sodium in your body
• A lack of vitamin B12 or other vitamin
• Certain medications
• Toxic action on nerves, such as that from lead, alcohol, or tobacco
• Radiation therapy