Restless leg syndrome (RLS) and periodic leg movement disorder (PLMD)

Restless Legs Syndrome is a neurological sensorimotor disorder that is characterized by an overwhelming urge to move the legs when they are at rest. The urge to move the legs is usually, but not always, accompanied by unpleasant sensations. It is less common but possible to have RLS symptoms in the arms, face, torso, and genital region. RLS symptoms occur during inactivity and movement or pressure temporarily relieves them. Symptoms of RLS are most severe in the evening and nighttime hours and can profoundly disrupt a patient's sleep and daily life. RLS symptoms often improve with medical treatment.

Periodic limb movements in sleep (PLMS) is a condition during sleep in which the limbs twitch or jerk every 20 to 40 seconds. Each movement lasts between half a second to five seconds and can involve the big toe, ankle, knee, and sometimes the hip, as well as jerking of the arms. Most jerking movements cause a brief awakening, as if every time you fell asleep, someone shook you just enough to wake you again. PLMD can cause poor sleep, which may lead to sleep maintenance insomnia and/or excessive daytime sleepiness.