As a physician, I’ve heard patients for 25 years tell me that their hands go numb when they sleep. Should this be something that worries you, or is it no big deal? After all, if you ask around, hands numb while sleeping isn’t a super common complaint of healthy people. Here’s why you should be concerned about this problem and what may be causing it.
First, you need to realize that when any body part goes numb, it means that the nerve supply to that area has been cut off. So your hands going numb while you sleep means that some nerve that goes from your neck to the hand is being compressed. Nerves have their own blood supply around the outside, so pressure on a nerve cuts off that blood supply and the nerve eventually is starved for oxygen and nutrients, making the nerve shut down. If this happens for a short period of time, the nerve just wakes up again once the pressure is removed. However, continued insult on the nerve can mean that it gets a little damaged with each episode. So months or years of numb hands at night can mean damaged nerves.
What usually causes this to happen? The biggest and most significant cause is neck (cervical) stenosis or a disc bulge, or when there’s little room in the neck bones due to arthritis or that disc for the nerves to travel or exit. You don’t have to have constant neck pain with stenosis or a disc bulge and some patients just notice that their hands are numb. When the neck gets into a weird position at night and the muscles that protect it during the day relax, the nerves get crunched and the hands go numb. Many times a cervical collar worn only at night will reduce the numbness. You may need to experiment with different collars or varying amounts of tightness (usually wearing it loosely while sitting at the side of the bed is enough, as the shoulders come up when you sleep and this makes the collar tighter). If this helps your hands, you likely need a cervical MRI to check this out.
The second biggest cause is thoracic outlet syndrome or TOS. This means that the nerves are getting crunched in the shoulder area. This is a common problem for modern computer users, as the shoulder and head come forward leading to nerve compression. There are some stretches in our book Orthopedics 2.0 for this issue. Other causes can include carpal tunnel syndrome in the wrists. This is when the main nerve of the hand (median nerve) gets pinched in the tunnel that it traverses in the wrist. Usually if this is the cause, simple wrist splints worn at night can be a huge help. However, both of these issues may require your doctor to take a closer look at the overarching cause of this problem.
One of the reasons you should be vigilant about getting this figured out is that these nerves being off line can cause other problems. The biggest concern is that other problems can crop up in the upper extremities that are caused by the nightly nerve compression. These include tennis and golfer’s elbow (lateral and medial epicondylitis) as well as arthritis in the hands and shoulder. How could this happen? The muscles protecting these areas go offline and the extra motion in the joint (which is imperceptible), ends up frying the joint over time. In addition, other new research shows that bad nerves may end up dumping nasty arthritis causing chemicals into the joints.
The upshot? Numbness in your hands at night is a big deal. It’s often ignored by physicians who aren’t experts in the area of musculoskeletal treatment, but take it seriously and find out its root cause. If you don’t, you’ll be wondering why your nerves are getting slowly less sensitive (changes in overall sensation) or why your shoulders, elbows, and hands ache all the time!