Changes

The sleeping urge is one among non-suppressible natural urges. [Cha. Sa. [[Sutra Sthana]] 7/ 3] Sleep is a function of the mind. All kinds of perception or connections with the external world are blocked in sleep. The mind is disconnected from all sensory and motor organs during sleep. [Patanjali Yoga Sutra 1/20]

The sleeping urge is one among non-suppressible natural urges. [Cha. Sa. [[Sutra Sthana]] 7/ 3] Sleep is a function of the mind. All kinds of perception or connections with the external world are blocked in sleep. The mind is disconnected from all sensory and motor organs during sleep. [Patanjali Yoga Sutra 1/20]

The normal sleep is responsible for happiness, nourishment, strength, virility, knowledge and liveliness. On the contrary, abnormal sleep can cause miseries, malnutrition, weakness, impotence, ignorance, and death. Untimely sleep, excessive and deprived can take away the good fortunes of life. Properly observed sleep can provide happiness. [Cha. Sa. [[Sutra Sthana]] 21/36-38] Those who resort to proper sleep are free from diseases, have pleasant attitudes, and are endowed with strength, complexion and virility. They are not too obese or too lean and have a longer lifespan with all prosperity. [Su. Sa. Sharira Sthana 4/39, 40]  

The normal sleep is responsible for happiness, nourishment, strength, virility, knowledge and liveliness. On the contrary, abnormal sleep can cause miseries, malnutrition, weakness, impotence, ignorance, and death. Untimely sleep, excessive and deprived can take away the good fortunes of life. Properly observed sleep can provide happiness. [Cha. Sa. [[Sutra Sthana]] 21/36-38] Those who resort to proper sleep are free from diseases, have pleasant attitudes, and are endowed with strength, complexion and virility. They are not too obese or too lean and have a longer lifespan with all prosperity. [Su.Sa. Sharira Sthana 4/39, 40]  

Food and sleep are the determinants of obesity and emaciation. [Cha. Sa. [[Sutra Sthana]] 21/51] Night vigil causes dryness in body, while day sleep causes unctuousness. This leads to the aggravation of [[vata]] [[dosha]] and [[kapha]] [[dosha]] respectively. Sleeping in a sitting posture does not influence [[dosha]] equilibrium. It causes neither too dryness nor unctuousness. [Cha. Sa. [[Sutra Sthana]] 21/50]  

Food and sleep are the determinants of obesity and emaciation. [Cha. Sa. [[Sutra Sthana]] 21/51] Night vigil causes dryness in body, while day sleep causes unctuousness. This leads to the aggravation of [[vata]] [[dosha]] and [[kapha]] [[dosha]] respectively. Sleeping in a sitting posture does not influence [[dosha]] equilibrium. It causes neither too dryness nor unctuousness. [Cha. Sa. [[Sutra Sthana]] 21/50]  

==Etymology and derivation==

==Etymology and derivation==

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The word is derived from the Sanskrit word root “Nidi kutsyaayaam” by adding the suffix “rak”.<ref>Jha Srujan. Amarkosha online application</ref> It means sleep, sleepiness, sloth, dream, shutting, budding state, dead, dull, drowsiness etc.

The word is derived from the Sanskrit word root “Nidi kutsyaayaam” by adding the suffix “rak”.<ref name=jha>Jha Srujan. Amarkosha online application</ref> It means sleep, sleepiness, sloth, dream, shutting, budding state, dead, dull, drowsiness etc.

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==Synonyms==

==Synonyms==

Shayanam, swapa, swapna/ swapnam, samvesha, tandra, supti,<ref>Jha Srujan. Amarkosha online application</ref>  vaishnavi [Su. Sa. Sharira Sthana 4/33]

Shayanam, swapa, swapna/ swapnam, samvesha, tandra, supti,<ref name=jna/>  vaishnavi [Su. Sa. Sharira Sthana 4/33]

==Physiology of sleep==  

==Physiology of sleep==