Category
page 1Sleep medicine
sleep deprivation
condition of not having enough sleep

polysomnography
Polysomnography (PSG) is a multi-parameter type of sleep study and a diagnostic tool in sleep medicine. The test result is called a polysomnogram, also abbreviated PSG. The name is derived from Greek and Latin roots: the Greek πολύς (polus for "many, much", indicating many channels), the Latin somnus ("sleep"), and the Greek γράφειν (graphein, "to write").
sleep medicine
medical specialty or subspecialty devoted to the diagnosis and therapy of sleep disturbances and disorders

sleep debt
cumulative effect of not getting enough sleep

nightcap
drink taken shortly before bedtime
Sleep onset latency
quantitative measure of the tendency to fall asleep
free-running sleep
rare sleep pattern whereby the sleep schedule of a person shifts later every day
deep sleep therapy
psychiatric treatment
hypnogram
thumb|upright=1.3|alt=Example hypnogram for a normal, healthy adult. Within the first hour of sleep SWS is displayed. Cycles of REM and NREM sleep proceed. During the third cycle of sleep there are two brief wake states. During the second half of the sleep period more REM sleep is displayed and there is little SWS detected.|Example hypnogram of a normal, healthy adult Here, both stage 3 and stage 4 are shown; these are often combined as stage 3.