Causes of Finger Numbness
Finger numbness most often occurs due to compression, or entrapment, of a nerve that supplies sensation to the hand.
Decreased feeling in your fingers affects numerous aspects of everyday living, from texting to signing your name to using silverware. Common accompanying symptoms include abnormal sensations such as tingling, burning or prickling in the fingers and hands. Numbness that specifically affects your fingers most commonly results from compression of nerves that carry sensation signals from your hands.
Carpal Tunnel Syndrome
Carpal tunnel syndrome is a leading cause of finger numbness and affects an estimated 3.8 percent of the general population, as reported in a 2012 "Open Orthopaedics Journal" review article. The condition results from compression, or entrapment, of the median nerve as it passes through the carpal tunnel along with several tendons. The carpal tunnel is a rigid space with virtually no capacity to expand. This makes the median nerve vulnerable to compression at this site, which might be triggered by:
- Holding the wrist in a bent position for prolonged periods
- Repetitive hand movements
- Pregnancy
- Weight gain
Typical symptoms of carpal tunnel syndrome include numbness, tingling, burning and pain in the thumb and index, middle and ring fingers. These symptoms might extend into the forearm. Symptoms often come and go initially but tend to become more persistent as the condition progresses. Symptoms are frequently worse at night because many people sleep with their wrists in a bent position. Activities that require a bent wrist position, such as driving, can also aggravate the symptoms.
Cubital Tunnel Syndrome
Cubital tunnel syndrome involves entrapment of the ulnar nerve at the level of the elbow. The nerve passes through a narrow tunnel -- less than 2/10 of an inch wide -- between the middle and inner bony points of the elbow before traveling through the forearm to the hand. Compression of the nerve at the elbow typically causes aching pain on the inner aspect of the elbow along with numbness and/or tingling in the ring and little fingers and adjacent parts of the hand. Keeping the elbows bent for prolonged periods, such as when talking on the phone, or leaning on the elbows typically provokes these symptoms. Many people experience symptoms at night due to sleeping with their elbows bent. Those with a previous history of elbow trauma or elbow arthritis are at increased risk for cubital tunnel syndrome.
Tumors and Cysts
Tumors or cysts growing near and compressing any of the nerves that supply sensation to the hand can potentially cause finger and hand numbness on the affected side. Ganglion cysts are a common example. These noncancerous growths most commonly develop near the joints and tendons of the wrist, where they can compress one or more of the sensory nerves of the hand. Which fingers experience numbness depends on what nerves are compressed. Other types of bone and soft tissue tumors and cysts can similarly cause finger numbness, even if they are too small or deep to cause a visible lump. Most tumors of the wrists and hands are not cancerous.
Pinched Neck Nerve
The nerves that supply sensation to the fingers and hands arise from the spinal cord in the neck. The nerve roots in this area can become compressed due to age-related changes in the spine or, less commonly, a herniated disc. Compression of nerve roots in this location -- known as cervical radiculopathy -- commonly causes numbness or tingling in one or more fingers and/or the thumb in addition to possible neck, shoulder or arm pain. Weakness of the hand and/or arm muscles also supplied by the affected nerve root(s) also frequently occurs.
Other Causes and Considerations
Finger numbness can occur with various medical conditions, though it is rarely the only symptom. For example, people living with autoimmune disorders such as rheumatoid arthritis or systemic lupus erythematosus may develop finger numbness and tingling due to involvement of the small blood vessels that supply the hand nerves. Peripheral neuropathy caused by diabetes, alcoholism or medications can also cause finger numbness, but this typically occurs only after the numbness has first developed in the feet. These are a few examples of other possible culprits for finger numbness.
Warnings and Precautions
See your doctor as soon as possible if you experience unexplained finger numbness. With entrapment syndromes, braces, ergonomic changes in your work environment, exercises and lifestyle changes can often limit or alleviate your symptoms.
Seek urgent medical care if you experience sudden numbness or tingling involving one hand or arm accompanied by weakness or paralysis as this could signal a stroke. Also seek immediate medical care if your finger numbness developed after a traumatic injury or in association with severe swelling of your arm or hand.
Reviewed and revised by: Tina M. St. John, M.D.