The peripheral nervous system consists of the nerves outside of the central nervous system, which consists of the brain and spinal cord. The peripheral nerves travel throughout the body and are responsible for providing sensation to the limbs and extremities and allowing fine movement. When peripheral nerves are compressed or damaged, abnormal body sensations, such as tingling in the hands, can result.
Carpal Tunnel Syndrome
The carpal tunnel is a narrow passageway located on the palm side of the wrist that protects one of the major nerves in the arm, called the median nerve, as well as nine tendons that allow the fingers to bend. Carpal tunnel syndrome occurs when the carpal tunnel exerts excess pressure on the median nerve. One of the most common causes of excess pressure on the median nerve is inflammation of the carpal tunnel due to repeated wrist movement, such as typing, according to MayoClinic.com. Some people may develop carpal tunnel syndrome as a result of a genetically narrow carpal tunnel. Those with carpal tunnel syndrome experience tingling and numbness in the hand and fingers, pain that radiates from the wrist to the arm and shoulders and down to the fingers, and weakness in the hands. MayoClinic.com notes that symptoms usually develop gradually. Depending on the cause, carpal tunnel syndrome may be treated with immobilization of the wrist, medications or surgery.
Ulnar Nerve Entrapment
The ulnar nerve is another major nerve in the arm that travels from underneath the collarbone all the way down to the fingers. Ulnar nerve entrapment occurs when the ulnar nerve becomes compressed anywhere along its length. The American Academy of Orthopaedic Surgeons notes that the compression usually occurs at the elbow. When the ulnar nerve becomes compressed, it results in various symptoms, including tingling in the hands and fingers, weakening of the grip and difficulties with finger coordination. If the compression is severe, it can also lead to muscle wasting in the hand. Most cases of ulnar nerve entrapment can be treated with immobilization of the joint and avoiding excess pressure on the elbow. Severe cases may require surgery.
Pernicious Anemia
Vitamin B12 is an important nutrient that is needed for proper formation of red blood cells as well as proper nervous system functioning. Pernicious anemia is a condition characterized by an inadequate amount of red blood cells in the body due to a lack of vitamin B12. A lack of B12 can develop as a result of insufficient dietary intake of vitamin B12 or diseases that cause vitamin B12 malabsorption, such as celiac disease or Crohn's disease. When B12 is deficient in the body, it can lead to nervous system damage. This causes a variety of symptoms, including fatigue, shortness of breath, dizziness, headache, increased sensitivity to cold, pale skin, muscle weakness, loss of reflexes, and tingling in the hands and feet. Those with pernicious anemia usually require lifelong B12 supplementation, either orally or by injection, according to the National Heart, Lung and Blood Institute.
