My Finger Is Numb. What Does That Mean?
One of Summit Orthopedics’ hand and wrist experts, Debra Parisi, M.D., discusses the most likely causes of numb fingers.
Our hands are an essential part of the way we interact with the world around us. From brushing hair out of our faces to typing an email or washing a dish, we use our hands all day long. Pain in our hands, from arthritis or another reason, can affect our lives every minute of the day. But what about the opposite problem — numb fingers?
“Numbness or tingling in the fingers is most likely going to be due to some sort of nerve issue,” said Summit Orthopedics hand and wrist expert Debra Parisi, M.D.
Nerve problems affecting the fingers fall into two broad categories:
Numb finger cause 1: compression
The most common cause of numbness in the fingers is compression of one of the nerves that supply sensation to the hand. The radial, median, and ulnar nerves all work to send signals between the hand and the brain, enabling us to move fingers and feel things with them.
Carpal tunnel syndrome is the most common type of nerve compression affecting the hand. The carpal tunnel is a narrow space in the wrist that is shared by the median nerve as well as the tendons that move the fingers. When there is too much pressure on the median nerve, it can result in numb fingers or tingling in the fingers. (It can also cause pain in the wrist or hand.)
The ulnar nerve can get pinched behind the elbow, a condition called cubital tunnel syndrome. This can cause a “funny bone feeling” of tingling around the elbow. However, more commonly it will cause numbness or tingling in the ring and small fingers of the hand or pain in the forearm or wrist.
The radial nerve, which supplies feeling to the back of the hand, can be compressed from that outside by a watch strap or too-tight band around the wrist. Often by simply loosening the band, feeling will be restored to the numb finger.
Lastly, the nerves that supply a finger (typically the index or middle finger) can get compressed when you carry too many heavy plastic grocery bags with your fingers. The weight presses down, and the bag may twist as you carry it. This compression can cause numbness and tingling in the involved finger. Numb fingers with this cause usually get better on their own after a few days.
Numb finger cause 2: nerve injury
When an injury stretches or severs a nerve, it stops working either temporarily or permanently, resulting in numbness and tingling. If the nerve carries motor fibers, weakness can also result.
The most common cause of nerve injury in the hand is a penetrating wound such as a wound caused by an accident with a kitchen knife. Other common causes are lacerations from broken glass and car accidents.
How to tell if the numb finger is an emergency
Numbness in one arm can be a sign of a stroke or other serious condition. How can you tell if the numbness you are experiencing is an emergency?
“Numbness caused by nerve compression starts gradually and gets worse over time. A stroke is different because it starts very suddenly,” Dr. Parisi said.
Additionally, it is uncommon for a stroke to just affect one arm or hand. Typically, symptoms will affect the entire side of the body. Finally, patients will often have other symptoms with a stroke, including problems with coordination, vision changes, or difficulty with speech.
People who have compressed nerves typically find that their symptoms tend to start at night. The symptoms start with pain or a tingly sensation as though the hand is falling asleep. Over the next few weeks or months, numbness starts to develop.
How is numbness in the fingers treated?
Treatment options for numb finger symptoms caused by nerve compression focus on taking pressure off the nerve. Treatments include splinting and bracing to keep the joint straight at night. In most cases this helps to take pressure off the nerve, reducing the nerve irritation and making symptoms better.
If these treatments are not successful, surgical options are available as well. “For conditions where there is too much pressure on the nerve, there are surgeries we can perform to open up the ligaments that form the roof of the carpal or cubital tunnel, creating more space for the nerve. We can repair nerve lacerations surgically,” Dr. Parisi said.
Summit Orthopedics provides personalized hand and wrist expertise
Our hands connect through our wrists and arms to our shoulders; a problem anywhere along our arm may have a big impact on hand function and quality of life. If you experience an injury or uncomfortable symptoms, our fellowship-trained hand and wrist surgeons are here to help. Summit physicians receive the highest levels of training and exclusively provide individualized care for conditions of the hand, wrist, and elbow.
Summit has convenient locations across the Minneapolis-St. Paul metro area, serving Minnesota and western Wisconsin. We have state-of-the-art centers for comprehensive orthopedic care in Eagan, MN, Plymouth, MN, Vadnais Heights, MN, and Woodbury, MN, as well as additional community clinics throughout the metro and southern Minnesota.
More resources for you:
Upper extremity surgeon Dr. Parisi recommends a checklist of questions for patients considering hand surgery.
Our hands are complex and essential tools. This overview explains the anatomy of the hand, and the structures that make our hands such dependable helpers.