Sleep debt

Sleep debt or sleep deficit is the cumulative effect of not getting enough sleep. A large sleep debt may lead to mental and/or physical fatigue.

There are two kinds of sleep debt; partial sleep deprivation and total sleep deprivation. Partial sleep deprivation occurs when a person or a lab animal sleeps too little for many days or weeks. Total sleep deprivation means being kept awake for days or weeks. There is debate in the scientific community over the specifics of sleep debt, and it is not considered to be a disorder.

Scientific debate

There is debate among researchers as to whether the concept of sleep debt describes a measurable phenomenon. The September 2004 issue of the journal Sleep contained dueling editorials from two leading sleep researchers, David F. Dinges and Jim Horne.

A 1997 experiment conducted by psychiatrists at the University of Pennsylvania School of Medicine suggested that cumulative nocturnal sleep debt affects daytime sleepiness, particularly on the first, second, sixth, and seventh days of sleep restriction.