Sleep studies are indicated in patients with sleep disorders such as excessive daytime sleepiness, restless leg movements at night, narcolepsy. Patients with Parkinsonian diseases may have REM sleep disorders, which can be evaluated by, sleep studies and treated.

Night terrors in children are non-Rem sleep disorders and often misdiagnosed as nocturnal epilepsy. Sleep studies in such children help in reaching the correct diagnosis, which will facilitate appropriate therapy.