Ever get that creepy crawly sensation in your legs when you’re in bed, that feeling that just makes you want to move or kick your legs to feel more comfortable?  If so, you’re not alone.  Millions of Americans suffer from a clinical disorder called restless leg syndrome (RLS).  It’s a very prevalent–but often underrecognized and underdiagnosed–problem in which you feel compelled to move your legs at night due to the discomfort that comes when the legs are still.  It’s a form of neurologic movement disorder, really, but it is also a sleep disorder because it’s hard to fall and stay asleep when your legs are moving and kicking all evening long.

Nothing fancy is necessary to diagnose the problem; sleep study testing is usually not needed.  Proper diagnosis requires an astute physician who listens to your problem and understands the nature of your symptoms.  There are four essential clinical criteria necessary to make the diagnosis of RLS (¹,²):

1.  An urge to move the legs, usually accompanied or caused by uncomfortable and/or unpleasant sensations in the legs.  Sometimes the urge to move is present without much preceding discomfort and sometimes the arms or other body parts are involved in addition to the legs.

2.  The urge to move or unpleasant sensations begin or worsen during periods of rest or physical inactivity such as lying down or sitting.

3.  The urge to move or unpleasant sensations are partially or completely relieved by movement, such as kicking, walking or stretching, at least as long as the activity continues.

4.  The urge to move or unpleasant sensations are worse in the evening or night than during the day or only occur in the evening or night; in other words, there is a diurnal nature to the symptoms.  When symptoms are severe, the worsening at night may not be noticeable but have been present earlier in the day.

RLS is more common in women than in men.  There can be a family history of RLS; many RLS sufferers have family members with similar or identical symptoms.  If there are family members that also have RLS, the age of onset for RLS for an individual is generally earlier than for those without a family history of RLS.  For most people the age of onset is generally in the 40’s to 50’s, and generally the prevalence and the severity of RLS tend to increase with advancing age.

Though often RLS is “primary,” in other words, not clearly caused by another medical problem, there are some clinical entities that can be associated with RLS.  The most common of these is iron deficiency.  Pregnancy and kidney disease can also be associated with RLS.  RLS can in some cases be made worse in the setting of alcohol or caffeine use.

The actual discomfort can be difficult for patients to describe; in fact, when I ask my patients how they would describe it, the most common response is, “Well, I can’t really quite explain it to you, how it feels.”  People often use “creepy-crawly” or “heeby-jeeby” to describe the sensation.  My friend Brad Vaughn, a preeminent physician sleep specialist at the University of North Carolina School of Medicine, has a humorous lecture slide that lists the dozens of descriptive terms his patients have used over the years; the ones I particularly like are “soda bubbles,” “jimmy legs,” “Elvis legs,” and “crawling bones.”

It’s important to recognize that a lot of things can look like RLS.  Vascular disease, for example, can cause leg discomfort, but this is usually localized to a specific area of the leg, and in the case of claudication, in which a leg artery is compromised, physical movements make the leg feel worse, not better.  Arthritis is localized to the joints as opposed to other parts of the legs.  Cramping refers to a sustained, painful muscular contraction (often involving the calf muscles) as opposed to voluntary, brief leg movements that arise due to RLS.  And then, finally, there are those who simply make those repetitive “nervous” movements of the leg; we’ve all seen that.  Such movements are not generated by leg discomfort, but often occur out of habit and are not physically abnormal per se.

Every time I give a public talk about sleep and ask who in the audience has these symptoms, it’s always surprising how many hands shoot straight up. Often this problem does not come to the attention of the doctor because people “learn to live” with it through the years, even though their leg movements are driving their spouses or bed partners crazy. You wouldn’t believe what some people go through, living with this disorder. In severe cases, lifestyles completely change. RLS tends to occur in the setting of “imposed rest.” So imagine trying to sit through a movie while your legs are moving the whole time. Or being stuck in the middle seat on a plane. Or having a formal dinner or other important evening occasion. The RLS can make you miserable in such settings.

RLS is imminently treatable if you inform your doctor of what is happening to you at night. Many times patients come to see me for some other matter pertaining to sleep, and the presence of RLS turns out to be an incidental finding, or sometimes even the underlying root cause for the primary problem. People have visited me for severe insomnia, for example, and the underlying RLS, never before mentioned to anybody, turned out to be the cause.

I’ll save discussion regarding workup and treatment for another entry.  The bottom line for this post, however:  if you have the symptoms consistent with the four RLS criteria above, do yourself a favor and inform your doctor.  Treatments can really be a lifechanger.

¹.  Allen RP et al.  Sleep Med.  2003;4(2):101-119

².  Garcia-Borreguero D et al.  Sleep Med. Rev. 2006;10(3)153-167