Numerous conditions can cause left arm nerve pain, or neuralgia, which is pain that follows the course of a nerve. There are many points in the upper extremities at which nerves can become entrapped, compressed or irritated. MedlinePlus states that neuralgia is most common among the elderly, although it can occur at any age. In some cases, the cause of neuralgia is unknown.
Ulnar Neuritis
According to the American Society for Surgery of the Hand, or ASSH, ulnar neuritis, also known as cubital tunnel syndrome, occurs when the ulnar nerve--one of the largest nerves in the upper extremity--is compressed or squeezed as it passes through the cubital tunnel, a small passageway located next to the bony bump on the inside edge of the elbow called the medial epicondyle. Any additional pressure in this area can press the ulnar nerve against the bone, causing pain, numbness and tingling in the elbow, forearm, hand and fingers on the affected side. Other possible signs and symptoms associated with ulnar neuritis include muscle weakness, clumsiness, loss of sensation, and loss of muscle mass and strength in the hand muscles. The ASSH states that one of the most common causes of ulnar neuritis is leaning forward on the elbows or holding the elbows in a bent position for prolonged periods.
Carpal Tunnel Syndrome
The National Institute of Neurological Disorders and Stroke, or NINDS, states that carpal tunnel syndrome is a condition in which the median nerve--one of the most important nerves in the upper extremity--becomes squeezed as it passes through the carpal tunnel in the wrist. The carpal tunnel is a narrow passageway through which the median nerve and several tendons pass. The median nerve is responsible for supplying sensation to part of the hand and several small hand muscles. Common signs and symptoms associated with carpal tunnel syndrome include pain that radiates from the wrist up the arm to the shoulder, burning, tingling or numbness in parts of the fingers or hand, the sensation of hand weakness and increased clumsiness. According to NINDS, carpal tunnel syndrome may be caused by a smaller than normal carpal tunnel, which is a congenital predisposition for carpal tunnel syndrome. However, any condition that places pressure on the median nerve as it passes through the carpal tunnel--including tumors or cysts--can cause carpal tunnel syndrome.
Radial Nerve Dysfunction
According to MedlinePlus, radial nerve dysfunction is a problem with the tissues and structures that the radial nerve--one of the most significant nerves coursing through the arms--innervates or enlivens. A person with radial nerve dysfunction may experience reduced movement or sensation in the triceps area, forearm or hand. MedlinePlus states that radial nerve dysfunction is a type of peripheral neuropathy. Possible causes of radial nerve dysfunction include the improper use of crutches, fracture of the humerus or upper arm bone, a tight wristwatch, trauma, compression of the radial nerve while sleeping and long-term pressure on the nerve. Common signs and symptoms associated with radial nerve dysfunction include abnormal sensations, pain, numbness and tingling throughout the forearm, hand and fingers on the affected side, and difficulty extending the wrist and the elbow.
