Patients are similarly asked to self-report their sleep habits with a week-long sleep diary to document when they go to bed, when they wake up, etc. to supplement the actigraphy data. Collecting this data allows sleep professionals to carefully document and measure patients sleep habits and confirm patterns described in their sleep history.Other additional ways to classify the nature of a patients sleep and biological clock are the morningness-eveningness questionnaire (MEQ) and the Munich ChronoType Questionnaire, both of which have fairly strong correlations with accurately reporting phase advanced or delayed sleep. Questionnaires like the Pittsburgh Sleep Quality Index (PSQI) and the Insomnia Severity Index (ISI) help gauge the severity of sleep disruption. Specifically, these questionnaires can help the professional assess the patients problems with sleep latency, undesired early-morning wakefulness, and problems with falling or staying asleep.Tayside childrens sleep questionnaire is a ten-item questionnaire for sleep disorders in children aged between one and five years old. Types
Currently, the International Classification of Sleep Disorders (ICSD-3) lists 6 disorders under the category of circadian rhythm sleep disorders.CRSDs can be categorized into two groups based on their underlying mechanisms: The first category is composed of disorders where the endogenous oscillator has been altered, known as intrinsic type disorders. The second category consists of disorders in which the external environment and the endogenous circadian clock are misaligned, called extrinsic type CRSDs. Intrinsic
Delayed sleep phase disorder (DSPD): Individuals who have been diagnosed with delayed sleep phase disorder have sleep-wake times which are delayed when compared to normal functioning individuals.
Normal rhythm
A circadian rhythm is an entrainable, endogenous, biological activity that has a period of roughly twenty-four hours. This internal time-keeping mechanism is centralized in the suprachiasmatic nucleus (SCN) of humans, and allows for the internal physiological mechanisms underlying sleep and alertness to become synchronized to external environmental cues, like the light-dark cycle. The SCN also sends signals to peripheral clocks in other organs, like the liver, to control processes such as glucose metabolism. Although these rhythms will persist in constant light or dark conditions, different Zeitgebers (time givers such as the light-dark cycle) give context to the clock and allow it to entrain and regulate expression of physiological processes to adjust to the changing environment. Genes that help control light-induced entrainment include positive regulators BMAL1 and CLOCK and negative regulators PER1 and CRY. A full circadian cycle can be described as a twenty-four hour circadian day, where circadian time zero (CT 0) marks the beginning of a subjective day for an organism and CT 12 marks the start of subjective night.Humans with regular circadian function have been shown to maintain regular sleep schedules, regulate daily rhythms in hormone secretion, and sustain oscillations in core body temperature. Even in the absence of Zeitgebers, humans will continue to maintain a roughly 24-hour rhythm in these biological activities.