Facts About Restless Legs Syndrome (RLS)
Other Possible Characteristics Include:
- Involuntary leg (and occasionally arm) movements while asleep;
- Difficulty falling asleep or staying asleep;
- Sleepiness or fatigue during the daytime;
- Cause of the leg discomfort not detected by medical tests;
- Family members with similar symptoms.
What Causes It?
Although the cause is unknown in most cases, certain factors may be
associated with RLS:
- Family history. RLS is known to run in some families -- parents may pass
the condition on to their children.
- Pregnancy. Some women experience RLS during pregnancy, especially in the
last months. The symptoms usually disappear after delivery.
- Low iron levels or anemia. Persons with these conditions may be prone to
developing RLS. The symptoms may improve once the iron level or anemia is
- Chronic diseases. Kidney failure quite often leads to RLS. Other chronic
diseases such as diabetes, rheumatoid arthritis, and peripheral neuropathy may
also be associated with RLS.
- Caffeine intake. Decreasing caffeine consumption may improve symptoms.
Who Gets RLS?
RLS occurs in both sexes. Symptoms can begin any time, but are usually more
common and more severe among older people. Young people who experience symptoms
of RLS are sometimes thought to have "growing pains" or may be considered
"hyperactive" because they cannot easily sit still in school.
How Is It Diagnosed?
There is no laboratory test that can make a diagnosis of RLS and, when
someone with RLS goes to see a doctor, there is usually nothing abnormal the
doctor can see or detect on examination. Diagnosis therefore depends on what a
person describes to the doctor. The history usually includes a description of
the typical leg sensations that lead to an urge to move the legs or walk. These
sensations are noted to worsen when the legs are at rest, for example, when
sitting or lying down and during the evening and night. The person with RLS may
complain about trouble sleeping or daytime sleepiness. In some cases, the bed
partner will complain about the person's leg movements and jerking during the
To help make a diagnosis, the doctor may ask about all current and past
medical problems, family history, and current medications. A complete physical
and neurological exam may help identify other conditions that may be associated
with RLS, such as nerve damage (neuropathy or a pinched nerve) or abnormalities
in the blood vessels. Basic laboratory tests may be done to assess general
health and to rule out anemia. Further studies depend on initial findings. In
some cases, a doctor may suggest an overnight sleep study to determine whether
PLMS or other sleep problems are present. In most people with RLS, no new
medical problem will be discovered during the physical exam or on any tests,
except the sleep study, which will detect PLMS if present.