Physiology of Nidra (Sleep)
Dr. Vandana Verma, Assistant Professor, Department of Kriya Sharira,
Faculty of Ayurveda, IMS, BHU, Varanasi
Nidra (Sleep)
Sleep is a natural body urge essential for nourishment and maintenance of health. The role of Nidra in maintenance of health has been well recognized by scholars of Ayurveda. It is one among the triupstambha (three sub-pillars) along with Aahar(diet) and Brahmcharya(celicbacy/ control over indriya). Ahara, Nidra and Brahmchrya are interdependent on each other as the quality of diet influences the sleep and vice –versa. For example intake of Kapha vardhak Aahar induces sleep while Vata vardhak Aahar causes Vata vriddhi that leads to less sleep. Similarly the time of sleep, duration of sleep may produce disturbance of digestion and metabolism. Few scholars of Ayurveda have considered the brahmacharya as celibacy or control over sexual activity. However Chakrapani has described the meaning of word Brahmacharya as Indryia sayam i.e. control over the sensory and motor organs. The control over the Indriya prevents the connection of Indriya with the objects or actions which are harmful to the body. By achieving the control over the Indriya the optimal health and real knowledge can be achieved.
Proper sleep at night is very essential to restore the physiology of the body. It is advised not to suppress the natural urge of sleep otherwise it will give rise to physiological disturbance leading to disorders.
त्रय उपस्तम्भा इति- आहारः, स्वप्नो, ब्रह्मचर्यमिति I (C.Su.11/35)
ब्रह्मचर्यशब्देन इन्द्रियसंयमसौमनस्यप्रभृतयो ब्रह्मज्ञानानुगुणा गृह्यन्ते| Chakrapani commentary
न वेगान् धारयेद्धीमाञ्जातान् —- न निद्राया निःश्वासस्य श्रमेण च||(C.su.7/4)
Mechanism of generation of sleep:
When the body, Indriya(sensory & motor organs) and mind get fatigued, they do not get connected with their respective stimulus or motor activity, then there is generation of sleep. Tama guna of mind and Sleshma(Kapaha dosha) are the cause for sleep. When the Hridaya and Manovaha srotas get occluded by Tama dosha then there is generation of sleep.
Satva guna of Mana is cause for awareness and perception of knowledge whereas Tama doha is cause for sleep.
यदा तु मनसि क्लान्ते कर्मात्मानः क्लमान्विताः | विषयेभ्यो निवर्तन्ते तदा स्वपिति मानवः||| (C.Su.21/35) तस्मिन् क्लान्त इति निष्क्रिये| कर्मात्मान इति इन्द्रियाणि| क्लमान्विताः क्रियारहिताः| विषयेभ्यः रूपादिभ्यः| मनसोऽप्रवृत्त्येन्द्रियाण्यपि न प्रवर्तन्त इति भावः| तदा स्वपितीति स्वप्नगुणयुक्तो भवति; स्वप्नश्च निरिन्द्रियप्रदेशे मनोवस्थानम् (Chakrapani commentary)
हृदयं चेतनास्थानमुक्तं सुश्रुत ! देहिनाम् | तमोभिभूते तस्मिंस्तु निद्रा विशति देहिनम् ||
निद्राहेतुस्तमः, सत्त्वं बोधने हेतुरुच्यते | स्वभाव एव वा हेतुर्गरीयान् परिकीर्त्यते || (S.Sha.4/34,35)चेतनासहचरितं मनोऽपि विशेषेण हृदयाधिष्ठानं मतम्| अतस्तस्मिन् हृदये तमसा तमोगुणेनोच्छ्रितेन आवृते निरुद्धे सति, सर्वप्राणिनः स्वपन्ति| (S.Sha.4/31 Dalhana commentary)
Sleep: Sleep is natural periodic state of rest of mind and body with closed eyes characterized by partial or complete loss of consciousness. The complete mechanism of sleep is still not understood it is hypothesized that the fatigue of reticular activating system (RAS) of brain induces sleep either by decreasing the discharge of impulses or by releasing inhibitory neurotransmitters like GABA or Serotonin. Loss of consciousness during sleep leads to decreased response to external stimuli and decreased body movements.
Types of sleep
Six types of sleep on the basis of cause- sleep induced due to Tama guna, Kapha dosha, fatigue of body and mind, Agantuki, due to some disorder.
तमोभवा श्लेष्मसमुद्भवा च मनःशरीरश्रमसम्भवा च| आगन्तुकी व्याध्यनुवर्तिनी च रात्रिस्वभावप्रभवा च निद्रा|| (C.Su.21/58)
Three types as per Sushruta :
Tamasi Nidra: Sleep induced due to Tama dosha of Mana , for example sleep in case of coma, person sleeps whole day and night .
Swabhawiki : Natural sleep is due to Tama guns and sleshma. In Satva dominant person deep sleep occurs at mid night while in Raja guna dominant person have no fixed pattern of sleep. Person get sleep sometimes in night and sometimes in day.
Vaikariki: sleep disturbances due to some disorders in the body as in case of decreased Kapka dosha and Increased Vata dosha there is loss of sleep or less sleep, pain in body and mind.
त्रिविधैव- तामसी, स्वाभाविकी, वैकारिकी चेति भेदेन II 1. तामसी :- तत्र यदा सञ्ज्ञावहानि स्रोतांसि तमोभूयिष्ठः श्लेष्मा प्रतिपद्यते तदा तामसी नाम निद्रा सम्भवत्यनवबोधिनी, सा प्रलयकाले; तमोभूयिष्ठानामहःसु निशासु च भवति I यद्यपि सर्वासामपि निद्राणां तमो हेतुस्तथाऽपि प्रकृष्टतमस्त्वात् तामसीयं निद्रा कथ्यते|
- स्वाभाविकी:- स्वाभाविकीमाह– तम इत्यादि| रजोभूयिष्ठानामनिमित्तं, (अनिमित्तमनियतकालं, चलत्वाद्रजसः कदाचिद्दिवा कदाचिद्रात्रावित्यर्थः) सत्त्वभूयिष्ठानामर्धरात्रे; (इति तस्मिन् काले किञ्चिदल्पीभूतं सत्त्वमुत्कटं च तमो भवति, तस्मादर्धरात्रे सात्त्विकाः स्वपन्ति)
- वैकारिकी: क्षीणश्लेष्मणामनिलबहुलानां मनःशरीराभितापवतां च नैव, सा वैकारिकी भवति || (S.Sha 4/32-33)
Time of sleep
The right time of natural sleep is night but if due to some reason there is night awakening, then the person can complete his sleep in the morning in empty stomach means without taking breakfast. Day time sleep causes increase in Snigdha(unctuous) property that increases Kapha dosha in body whereas night awaking causes Rukshata (dryness) and increase in Vata dosha. A short snap of sleep in sitting posture in day time do not produce dryness or unctuousness in body.
यथाकालमतो निद्रां रात्रौ सेवेत सात्म्यतः|| असात्म्याज्जागरादर्धं प्रातः स्वप्यादभुक्तवान्|| (A.S. Su.9/45, 46)
रात्रौ जागरणं रूक्षं स्निग्धं प्रस्वपनं दिवा| अरूक्षमनभिष्यन्दि त्वासीनप्रचलायितम्|| (C.Su.21/50)
Indications of Day sleep
Day sleep is allowed only in summer season, childhood, old age, emaciated person, weight loss, indigestion, suffering with diseases like dypnoea, hiccup, diarrhoea, pain, in state of Anger, Grief, and fear.
ग्रीष्मे त्वादानरूक्षाणां वर्धमाने च मारुते| रात्रीणां चातिसङ्क्षेपाद्दिवास्वप्नः प्रशस्यते||(C.Su.21/43)
ग्रीष्मवर्ज्येषु कालेषु दिवास्वप्नात् प्रकुप्यतः| श्लेष्मपित्ते दिवास्वप्नस्तस्मात्तेषु न शस्यते|| (C.Su.21/44)
गीताध्ययनमद्यस्त्रीकर्मभाराध्वकर्शिताः| अजीर्णिनः क्षताः क्षीणा वृद्धा बालास्तथाऽबलाः|| (C.Su.21/39)
तृष्णातीसारशूलार्ताः श्वासिनो हिक्किनः कृशाः| पतिताभिहतोन्मत्ताः क्लान्ता यानप्रजागरैः|| (C.Su.21/40)
क्रोधशोकभयक्लान्ता दिवास्वप्नोचिताश्च ये| सर्व एते दिवास्वप्नं सेवेरन् सार्वकालिकम्|| (C.Su.21/41)
धातुसाम्यं तथा ह्येषां बलं चाप्युपजायते| श्लेष्मा पुष्णाति चाङ्गानि स्थैर्यं भवति चायुषः|| (C.Su.21/ 42)
Persons unfit for day sleep
Obese, after intake of oily food, Kapha dominant, diseases produced due to Kapha dosha, person with chronic toxicity.
मेदस्विनः स्नेहनित्याः श्लेष्मलाः श्लेष्मरोगिणः| दूषीविषार्ताश्च दिवा न शयीरन् कदाचन||(C.Su.21/45)
Benefits of proper sleep and harmful effects of improper sleep
Proper sleep leads to Health, happiness, nourishment, strength, proper functions of indriya, Mana and buddhi, proper generation of knowledge. However improper sleep is cause for disease, sorrow, malnourishment, weakness, improper function of body and mind.
निद्रायत्तं सुखं दुःखं पुष्टिः कार्श्यं बलाबलम्| वृषता क्लीबता ज्ञानमज्ञानं जीवितं न च|| (C.Su.21/36)
अकालेऽतिप्रसङ्गाच्च न च निद्रा निषेविता| सुखायुषी पराकुर्यात् कालरात्रिरिवापरा||(C.Su.21/37)
सैव युक्ता पुनर्युङ्क्ते निद्रा देहं सुखायुषा| पुरुषं योगिनं सिद्ध्या सत्याबुद्धिरिवागता||(C.Su.21/38)
देहवृत्तौ यथाऽऽहारस्तथा स्वप्नः सुखो मतः| स्वप्नाहारसमुत्थे च स्थौल्यकार्श्ये विशेषतः||(C.Su.21/51)
Causes of loss of sleep(Insomnia)
Excess of Vata and Pitta dosha and mental stress and trauma is cause for improper sleep.
निद्रानाशोऽनिलात् पित्तान्मनस्तापात् क्षयादपि | सम्भवत्यभिघाताच्च प्रत्यनीकैः प्रशाम्यति ||
एत एव च विज्ञेया निद्रानाशस्य हेतवः| कालशीलक्षयो व्याधिर्वृद्धिश्चानिलपित्तयोः||(A.S. Su.9/42) कालश्च निद्रानाशहेतुः येन प्रभातादौ सा न भवति| शीलमभ्यासः तेन यस्य यस्य यस्मिन् काले निद्रानिवृत्तिरभ्यस्ता तस्य तस्य तस्मिन् काले सा भवतीति|
Effects of suppression urge of sleep
Suppression of urge of sleep causes body ache, feeling of heaviness in body, yawing, stiffness in body, loss of orientation, indigestion, drowsiness, and disorders of Vata dosha.
निद्रानाशादङ्गमर्द्दशिरोगौरवजृम्भिकाः| जाड्यग्लानिभ्रमापक्तितन्द्रारोगाश्च वातजाः||(A.S. Su.9/46)
- Diseases produced due to day sleep (दिवास्वप्न)
Jaundice, headache, numbness, feeling of heaviness, malaise, loss of digestive capacity, feeling of heaviness in chest.
हलीमकः शिरःशूलं स्तैमित्यं गुरुगात्रता| अङ्गमर्दोऽग्निनाशश्च प्रलेपो हृदयस्य च|| (C.Su.21/46)
Odema, Anorexia, nausea, coryza, hemicrania, urticaria, abscess, itching, drowsiness, cough, diseases of throat.
शोफारोचकहृल्लासपीनसार्धावभेदकाः| कोठारुःपिडकाः कण्डूस्तन्द्रा कासो गलामयाः||(C.Su.21/47)
Improper functioning of intellect, loss of memory, obstruction in channels, fever, improper functioning of intellect and sense and motor organs, increased toxic effect of various toxins.
स्मृतिबुद्धिप्रमोहश्च संरोधः स्रोतसां ज्वरः| इन्द्रियाणामसामर्थ्यं विषवेगप्रवर्त(र्ध)नम्|| (C.Su.21/48)
तन्द्रा (Drowsiness)
Drowsiness is state just before sleep in which there is yawing, feeling of fatigue and heaviness in the body and inability of Indriya to connect with their stimulus or perform their action. The Kapha and Vata are responsible for the state of drowsiness. While the Raja and Pitta dosha are the cause for Vertigo (Bhram) and Pitta with Tama dosha for unconsciousness/syncope (Murccha).
इन्द्रियार्थेष्वसम्प्राप्तिर्गौरवं जृम्भणं क्लमः | निद्रार्तस्येव यस्येहा तस्य तन्द्रां विनिर्दिशेत् ||(S.Sha4/49)
मूर्च्छा पित्ततमःप्राया, रजःपित्तानिलाद्भ्रमः | तमोवातकफात्तन्द्रा, निद्रा श्लेष्मतमोभवा ||(S.Sha.4/56)
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Assessment: Multiple choice questions
Q.1. Night awakening causes………. .
- Vata dosha vriddhi
- Indigestion
- Dryness in the body
- All of the above
Q.2. Which statement is not true about the quality of sleep in a person.
- Sativka person have sleep at mid night
- Tamasika person have large duration of sleep than Satvika
- In a Rajasika person time of sleep is not fixed
- None
Q.3. If a person takes a snap of sleep in sitting posture, which of the following condition will occurs in body:
- Rukshta
- Snighdhata
- Nor Ruksha neither Snighdhta
- None
Q.4. Divaswapana(day sleep) is indicated in …….. ritu:
- Shishir
- Varsha
- Hemant
- Grishma
Q.5. Which factor is responsible for generation of sleep:
- Fatigued Indriya and Mana do not get connected to their subjects
- Mind perform its functions
- Indriya gets connected with their respective Arthas
- None
Q.6. Which type of Nidra is also known as bhootdhatri:
- Tamobhava
- Ratriswabhava prabhva
- Aagantuki
- Vyadhianuvartani
Q.7. Cause of Nidra nash(insomnia) is:
- Increased vata dosha
- Increased pitta dosha
- Manas santapa
- All of the above
Q.8. Which of following condition occur due to suppression of urge of sleep:
- Stiffness
- Heaviness
- Indigestion
- All of the above
Q.9 According to Charak, person fit for day sleep:
- Kapha dominant
- Obese
- Person suffering from indigestion
- Person suffering from Kaphaja disorders
Q.10 Benefits of proper sleep:
- Health
- Nourishment
- Proper perception of knowledge
- All of the above
Answer sheet for MCQ
| Question no | Answer | Question no | Answer |
| 1 | 4 | 6 | 2 |
| 2 | 4 | 7 | 4 |
| 3 | 3 | 8 | 4 |
| 4 | 4 | 9 | 3 |
| 5 | 1 | 10 | 4 |
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