Glossary

Anemia:
A blood disorder in which there is an insufficient amount of red blood cells which causes a lack of oxygen delivery to the body. Symptoms of anemia include fatigue, lack of energy and shortness of breath. Low iron levels can contribute to a worsening of RLS.8
Chronic sleep deprivation:
A state of repeated sleep disturbances that lead to inadequate amounts of sleep. Chronic sleep deprivation can have a strong impact on daily activities, affecting mood, energy, and the ability to concentrate. Because RLS symptoms often intensify at night and interfere with sleep, RLS sufferers often report sleep deprivation, which can be one of the chief complaints of the syndrome.8
Dopamine:
A chemical found in the brain that is necessary for transmitting messages from one brain cell to another. Dopamine plays a role in motor coordination, mood, short-term memory and balance. It is suspected that impaired transmission of dopamine signals may play a role in RLS.
Fatigue:
The state of being extremely tired and without energy.
Genetic component:
A trait, condition, or characteristic that is inherited, passed from parents to offspring. RLS often runs in families. In July 2007, researchers discovered a gene variant for primary RLS.7
Idiopathic restless legs syndrome (RLS):
Primary RLS that occurs without any known cause and is not the effect of a secondary disease (such as another underlying medical condition or in association with the use of certain drugs).
International Restless Legs Syndrome Study Group (IRLSSG):
An international group of investigators chosen for their significant contributions to the field of RLS research. This group defined the essential criteria for understanding and diagnosing RLS.
Iron deficiency:
A disorder that occurs when there is not enough iron in the body, causing problems with red blood cell production, muscle function, and numerous other biological processes. Underlying iron deficiency could be a cause of RLS, so supplementing the diet with iron may help alleviate symptoms.8
Misdiagnosed:
A term used to describe an incorrect health care professional’s diagnosis of a particular disorder or condition.
Movement disorder:
A group of neurological conditions that affect the speed, fluency, quality and ease of movement. Abnormal fluency or speed of movement may involve slowed or absent voluntary movement or excessive or involuntary movement, such as RLS.
National Institutes of Health (NIH):
An administrative heart of biomedical research in the United States that is responsible for the activities of a number of leading research centers.
Nocturnal leg cramps:
Muscle spasms that are painful, uncontrolled and occur during the night.
Periodic limb movements during sleep (PLMS):
A disorder characterized by repetitive movements that occur while sleeping. If left untreated, PLMS can cause chronic sleep deprivation.
Quality of life:
A scientific measure of personal wellbeing.
Restless legs syndrome (RLS):
A sensorimotor disorder characterized by a distressing urge to move the legs, or affected limb, usually accompanied by an uncomfortable sensation or pain in the legs or other affected body parts. RLS is triggered by inactivity and the symptoms are temporarily relieved by movement. Symptoms are usually worse at night. The condition can be relatively mild or may be profoundly disruptive, leading to sleep disturbance, daytime exhaustion and diminished quality of life.
Secondary restless legs syndrome (RLS):
RLS symptoms that occur due to a secondary condition, like pregnancy, anemia or iron deficiency, or sometimes by using certain drugs. Secondary RLS usually will go away once the underlying medical condition has been treated.
Sensorimotor:
A term used to describe the combination and interaction of sensory and motor effects.
Sleep disorders:
A group of conditions characterized by an inability to have normal, restful sleep.
Underdiagnosis:
A term used to describe the lack of a health care professional diagnosis of a particular disorder or condition.