Sleeptime

Sleeptime refers to the period during which an organism is asleep, typically occurring at night and characterized by reduced responsiveness to the external environment and decreased voluntary movement. Sleep is governed by a circadian system and homeostatic sleep pressure, which together regulate when sleeptime occurs and how long it lasts.

Sleep duration recommendations vary by age. Infants often require 12 to 16 hours, including naps; toddlers about 11 to 14 hours; school-age children 9 to 11 hours; teenagers 8 to 10 hours; adults 7 to 9 hours; older adults 7 to 8 hours. Individual needs vary with genetics, health, and lifestyle.

Sleep comprises stages including non-REM and REM sleep, cycling every 90 to 120 minutes. Adequate sleeptime supports memory consolidation, metabolic health, mood, and immune function. Insufficient sleep or fragmented sleeptime is linked to mood disorders, impaired cognition, weight gain, and increased accident risk.

Factors influencing sleeptime include light exposure, caffeine, physical activity, and shift work. Sleep hygiene practices such as maintaining a regular schedule, a comfortable sleep environment, and reducing blue light exposure can improve sleeptime. Sleep disorders such as insomnia and sleep apnea can alter sleeptime and should be diagnosed and managed by clinicians.