What is Numbness?
Numbness and tingling are abnormal sensations that can occur anywhere in your body, but are often felt in your hands, feet, arms, or legs. Some other terms that are used to describe numbness are sensory loss, paresthesias, tingling, and loss of sensation.

What are the Causes?
Numbness and tingling have many different possible causes, including:

  • Remaining in the same seated or standing position for a long time
  • Injuring the particular nerve supplying the body part where you feel the sensation
  • Lack of blood supply to the area. For example, plaque buildup from atherosclerosis in the legs can cause pain, numbness, and tingling while walking
  • Pressure on the spinal nerves, like that from a herniated disc or fibrotic tissue
  • Carpal tunnel syndrome can cause numbness or tingling in your wrist, fingers, hand, or forearm
  • Certain medical conditions, including diabetes, an under active thyroid, multiple sclerosis, seizures, or migraine headaches
  • Changes in electrolytes, like abnormal levels of calcium, potassium, or sodium in your body
  • Vitamin B12 deficiency
  • Transient ischemic attack (TIA) or stroke
  • Certain medications, including chemotherapy for cancer, chloroquine for malaria, D-penicillamine, isoniazid for tuberculosis, nitrofurantoin, gold therapy for rheumatoid arthritis, or phenytoin for seizures
  • Toxic action on nerves, such as that from lead, alcohol, or tobacco

Where will it Occur?
The injury often times is in the neck, back, wrist, elbow, and leg but can occur anywhere in your body. If you have a neck injury, for example, you may feel the sensation anywhere along your arm or hand. Similarly, a low back injury can cause sciatica — a sensation of numbness or tingling down the back of your leg.