Sleep was, in "every sentient being in the universe", an essential (TV: Sleep No More) periodic state of physiological rest during which the body was not active and the mind was unconscious. Both the human and Gallifreyan species slept with their eyes closed. However, while humans normally required a full night's sleep, Gallifreyans could make do with as little as an hour. (PROSE: The Highlanders, AUDIO: Davros) The Doctor was known to have extra adventures while their companions were asleep. (HOMEVID: Bad Night, Clara and the TARDIS) In emoji, 😴 was the symbol used to denote a sleep state. (TV: Smile)



  5. running.


Although a sleeping individual appeared entirely inactive, some functions of their brain were actually more active than during wakefulness. The high amplitude brain waves known as delta waves were associated with sleep. (TV: Kinda) When sleeping, series of thoughts, images, or emotions known as dreams could occur. (TV: The Time Monster)



As a Time Lord, the Doctor did not require much sleep. (AUDIO: Retail Therapy, World Enough and Time, HOMEVID: Good Night, TV: Knock Knock) Though they did not do so often, (AUDIO: Their Finest Hour) the Doctor did sleep on occasion, (AUDIO: The Unknown, TV: Sleep No More) particularly after regeneration, (TV: Sleep No More; TV: Spearhead from Space, Robot, Castrovalva, Time and the Rani, The Christmas Invasion, Deep Breath, The Woman Who Fell to Earth) a big lunch, (TV: Sleep No More; TV: The Two Doctors) or when no one was looking, (TV: Sleep No More; AUDIO: The War Valeyard) and the Tenth Doctor did have a bedroom aboard the TARDIS. (COMIC: A Rose by Any Other Name) The Eighth Doctor claimed only to need a little sleep "every month or seven". (AUDIO: The War Valeyard) The Doctor often expressed that "Sleep is for tortoises", specifically in their fourth, (TV: The Talons of Weng-Chiang) fifth (AUDIO: A Requiem for the Doctor) and twelfth incarnations. (TV: Knock Knock) Nevertheless, the Twelfth Doctor thought that sleep was wonderful. (TV: Sleep No More)

Jack Harkness once claimed that he doesn't sleep. (TV: Ghost Machine)

The transitional state between waking and sleeping was known as Hypnagogia. (AUDIO: The Belly of the Beast)
