Periodic limb movements in sleep

Dear Dr Margaret
My partner says I keep kicking him in the night when I’m asleep, and he’s fed up with it. I don’t know that I am doing it, but it must be when I’m dreaming. How can I stop dreaming?

I do not know of any way to stop dreaming. Even if there were possible, it would not be a good idea, because dreaming is part of healthy sleep (although its function is still a mystery). In any case, I doubt that the reason you kick is that you are ‘acting out’ a dream. This might happen occasionally, but is unlikely to make you kick throughout the night.

You probably have what doctors call ‘periodic limb movements in sleep (PLMS)’. Mostly, these are movements of the legs, but some people move their arms as well. They are repetitive movements, occurring every 15-40 seconds in bouts. There may be hundreds of these movements each night. Each movement may be quite slow (taking up to 10 seconds), but your partner would experience them as kicks. They are different from the brief and sudden jerks that we all experience occasionally just as we are falling asleep.

It is reasonable to think that PLMS would occur when you are dreaming, but this is not the case. During sleep, we alternate between dreaming and periods when we are not dreaming. PLMS occur during non-dreaming sleep.

Ask your partner to observe the kicks, so he can tell you exactly what happens. Do you bend your ankle, knee and hip, while at the same time straightening your toes? If so, you almost certainly have PLMS. Another clue is having restless legs syndrome, in which you experience uncomfortable creeping feelings in your legs when you are trying to get to sleep. About 80% of people with restless legs also have PLMS.

This problem is much more common than you may realize. Although PLMS can occur at any age, they are more likely in older people. Some people have them only during pregnancy.

Dealing with them can be difficult. Look at our restless legs section – some of the advice there may help. Caffeine is a potent cause of PLMS, so choose decaffeinated tea/coffee and avoid cola drinks. If you are on antidepressants, talk to your doctor because some antidepressants can make PLMS more likely. There is some effective drug treatment (dopamine agonists) for PLMS, but you would need to discuss the pros and cons fully with your doctor. My view is that it would be inappropriate to take medication for a condition that is not harmful to your health and is not giving you any symptoms. Separate beds seem like the answer.