By Simeon Margolis, M.D., Ph.D.
Restless legs syndrome (RLS) does not refer to a desire to travel to far-off places. Rather, RLS is a rather common condition characterized by discomfort, usually below the knees and in both legs, that occurs only when a person is at rest. Symptoms are rapidly but only temporarily relieved by movement.
The discomfort attending RLS may be felt as a crawling, itching, or stretching sensation deep beneath the skin. Symptoms become worse towards the end of the day and may start while you are reading the paper in a comfortable chair after dinner. Symptoms reach their peak at night, however, frequently beginning shortly after lying down in bed. The resulting involuntary jerking movements of the legs can interfere with sleep. Sufferers with mild symptoms may fidget, move around in the bed, and kick or massage the legs in an effort to relieve symptoms. When symptoms are more severe, people may try pacing the floor for relief.
RLS is more common in women and its prevalence increases with age. In 1 survey, for example, RLS symptoms occurred on 5 or more nights per month in 3 percent of individuals between ages 18 and 29, 10 percent of those ages 30 to 79, and 19 percent of people aged 80 or older. RLS occurs with increased frequency in patients on dialysis for kidney failure and in those with diabetic peripheral neuropathy.
The cause of RLS is unknown, but sufferers often have a family history of the disorder and researchers have identified a few genes associated with RLS. Several studies have suggested that RLS is associated with iron deficiency, and some reports describe relief of symptoms when a deficiency is corrected by taking iron pills.
If your RLS-like symptoms are keeping you (or your spouse) awake at night, it would be worth a trip to your doctor even though there is no way to make the diagnosis and no surefire treatment. A blood test might show iron deficiency and make a trial of iron pills worthwhile. And since RLS comes on during situations that make a person sleepy—inactivity, sitting still, boredom—doing some "alerting activities" that wake up the mind can sometimes temporarily alleviate your symptoms at these times. Alerting activities include playing video or card games, doing crossword puzzles or needlework, or even reading a gripping novel. On the other hand, caffeine, alcohol, and smoking can all aggravate symptoms, and should be avoided.
If none of these measures work, your doctor might prescribe one of a number of different medications that have shown variable success in relieving RLS symptoms. The problem is not only that these drugs might fail to lessen symptoms but also that their cost and possible side effects might be prohibitive. And, in the absence of a sure way to make the diagnosis, there's always the possibility that you may not even have RLS.