It's a question we get a lot at Total Performance Physical Therapy, and unfortunately the truth is, like most cases, there's not one definite answer.
There are many different causes for your hand to develop paraesthesias, or commonly described as "pins and needles" or uncomfortable tingling. Your skin is filled with tiny nerve endings that relay signals to the brain regarding sensation. When these nerves are interrupted during signaling to the brain, which can be caused by compression, pulling, inflammation, or having reduced blood supply to the nerve, the skin feels a sensation of prickling and tingling.
The most important thing to note is that tingling can most often be a fore warning of worse things to come, like loss of muscle in the hands and arm. Often people report a tingling sensation and then, after ignoring it for a while, report difficulty holding a glass or using the hand.
First I'll explain the most common reasons people develop pins and needles in their hands and then how physical therapy can help the common condition.
Nerve Compression: It means just that; your nerves are being compressed. Trapped nerves at the neck, shoulder, around the elbow, the forearm, and even wrist, can affect the hand. This pain can be either short or long in duration depending on the problem causing the pain. Some common reasons for short lived pins and needles can be as simple as leaning on your forearms, wrists, or hands at your desk or carrying a heavy bag around your shoulder, arm, and wrist. However, in more severe cases the nerves can be compressed due to overuse injuries caused by inflammation and swelling in the arm, wrist, and hand or by abnormalities in bone/muscle structure. Here are the more common causes of nerve compression:
Carpel Tunnel: This syndrome involves the median nerve in your arm, which supplies sensation to the thumb, index, middle, and half of your ring finger. When the muscles of the front of your wrist get over worked or are used too much they become inflamed and swollen. The median nerve then gets trapped in a thick ring-like sheath surrounding your wrist and causes added pressure to this tunnel and puts an abnormal pressure on all the structures inside of it. As a result, the nerve is compressed and you feel a sensation of tingles in the areas of the front of your hand near the thumb, index, and middle finger.
Thoracic outlet syndrome: Many of the nerves and blood vessels in the shoulder all the way down into the hand come from what's called the "brachial plexus," which is a bunch of nerves that come from the neck and branch off into the arm, forearm, wrist, and hand. However, these nerves have to pass through the thoracic outlet, or a small space composed of a lining of bone and muscles by your neck. When this space becomes smaller, which can be due to tight musculature of the neck, poor posture, and poor body alignment, nerves and blood vessels can become compressed. This can cause a reaction down the nerve all the way into the hand, causing numbness and pins and needles.
Think about how most people sit at a computer, after awhile their shoulders slump forward, this exact posture winds up creating thoracic outlet syndrome compressing the nerves and causing tingling. If it gets bad enough, it can cause loss of muscle, like losing the ability to grip things.
Cervical Root Radiculopathy: There are many causes of cervical root radiculopathy, including herniated discs or bulging discs, spinal root compression, and spinal instability. All of these diagnoses can cause the roots of the cervical spine, which turn into the nerves in your arms and hands as they work their way down, to become inflamed. So if the nerves in your neck are irritated, it can in turn affect signaling of the nerve all the way down into the hand. This type of pain usually, but not always, has arm tingling associated with it.
Swelling: The term swelling is used when there is an abundance of fluid in a localized or generalized area. In terms of pins and needles in the hand, swelling is commonly caused by, but not limited to, trauma from an object coming into direct contact with the body. If the hand, wrist or arm undergoes a trauma, the body's natural response is to fix the tissues and structures that were damaged by sending blood and other fluids to the site of trauma in order to help with the healing process. The abundance of fluid in the area causes severe pressure put on all items surrounding the area, including nerves. The nerve conduction can be decreased due to the pressure produced by the swelling. Women who are pregnant often experience tingles in the hand due to the fluid increase and retention that the body undergoes during pregnancy.
Decreased Circulation: One of the most common causes for pins and needles in the hand is decreased circulation. Everything in your body needs blood circulation to function properly, and believe it or not nerves are a big one. The more distal you go, meaning the further you go down your arms and legs, the smaller the arteries and veins, which help pump blood and bring them back to your heart. Over time, arteries can start to pump less blood, whether they become stiffened due to plaque build-up or you have a low resting blood pressure. Another reason for decreased circulation can be caused by poor posture, much like the previous example of thoracic outlet syndrome.
So, how can physical therapy help you if your hands are tingling?
Depending on the type of injury, physical therapy can provide a range of treatments in order to decrease the pins and needles felt in your hand. It is important to get help soon after noticing tingling in the hands and forearms, because sometimes putting it off in this case it can actually be too late.
In nerve compression injuries, the main focus is to decrease the pressure caused by the matter compressing it. For example, in carpal tunnel syndrome, physical therapy can work on tendon gliding of the wrist muscles to help decrease the amount of compression on the median nerve. Because compression syndromes can be caused by overuse injuries and postural issues, physical therapists will assist in postural management and education in order to decrease the inflammation and use of muscles that cause tendons to enlarge and cause compression on nerves. In cases of carpal tunnel, the physical therapist will often educate patients on proper wrist placement during every day and work related activities.
In thoracic outlet syndrome, postural education, strengthening, and stretching are important in order to restore proper muscle length and tension relationship, which includes stretching of tight muscles and strengthening of loose or weak muscles. If nerves are being compressed in the cervical spine, traction (light pulling/stretching) of the vertebrae in the neck, is used by therapists in order to decrease the pressure placed on the nerves being pinched.
If there is significant swelling, physical therapists can provide hands on manual therapy that helps with circulation of fluids in order to decrease swelling in an area to provide relief for nerves and other structures being compressed. They will also provide modalities in the form of ice to decrease the amount of fluid drawn to the area of injury.
If decreased circulation is the cause, whether it is from a postural issue decreasing circulation or a blood pressure issue, physical therapy can work on restoring a more normal posture and provide fitness education and exercise programs in order to improve cardiovascular health and blood transport throughout the body.