It happens when you least expect it: one minute your hand is functioning as usual, and then next it’s partially numb, but also feels like you’re getting pricked by pins and needles. In other words, your hand fell asleep.
The medical term for this is paresthesia, and it happens when pressure is placed on a nerve that supplies a limb.
According to Anthony Kouri, M.D., an orthopaedic surgeon at the University of Toledo Medical Center in the U.S., the most common reason our hand falls asleep is that we lie on it in a flexed position while we’re sleeping. This causes blood flow to be cut off from the nerve, which causes numbness or tingling.
Why and where this happens
The numbness from this is generally in the thumb, index and middle fingers, Kouri tells Lifehacker. If you experience numbness in the pinky and/or ring fingers, that is typically from your elbow being hyper-flexed while we sleep, causing compression and decreased blood flow to the ulnar nerve.
Meanwhile, if your entire arm is numb, that means you either slept on your shoulder the wrong way, decreasing blood flow to multiple nerves in the arm, or slept with your neck in a strange position, affecting the nerves coming directly from the spine, Kouri explains. At this point, your hand and/or arm can feel tingly - that “pins and needles” sensation - or just numb. Either way, you’re probably looking for a way to get rid of it.
How to get rid of the pins and needles
Whether this happens while we’re asleep or just sitting on the couch watching TV, our first reaction is often to shake the hand and/or arm to attempt to regain feeling in it, or get the pins and needles to go away. According to Kouri, doing this does help to improve blood flow to the nerve, but simply releasing the pressure from our sleeping or couch-sitting position will typically allow sensation to return.
You may also want to try clenching and then unclenching your fist, physician Nikola Djordjevic M.D. tells Lifehacker. “This method is able to get the blood flow to your hands and ease the nerves, thus relieving you from feeling pins and needles,” he says.
Is there a way to speed up the process?
While we’d love to report that there’s a quick hack that will make your hand feel normal again in a few seconds, unfortunately, one doesn’t exit. Kouri says that there is no existing data definitively ruling that one technique is faster than the other, but notes that anecdotally, it seems that sensation does return more quickly with shaking or clenching.
How to prevent pins and needles
If you notice that your hand is frequently asleep when you wake up in the morning, Kouri says there are a few things you can do to prevent this. First, check to see which fingers are affected.
If it is primarily your thumb, index and middle finger, you may want to try wearing over-the-counter neutral wrist braces at night. Conversely, if you notice that your pinky and ring finger are primarily affected, you can try wearing an elbow brace at night, or simply roll a towel and place it inside your elbow while you sleep. This will often prevent numbness when you wake up.
How to know if it’s a sign of something else
If you notice that your hands, arms, feet or legs are going numb on a regular basis and the techniques above don’t work, it could be the sign of another condition like carpal tunnel syndrome or multiple sclerosis. At this point, it’s a good idea to see a medical professional about it. But in most cases, feeling pins and needles in your hand just means it’s a temporarily pinched nerve and you should be back to normal soon.