PHYSIOLOGY OF SLEEP AND DREAMS

PHYSIOLOGY OF SLEEP AND DREAMS

• Sleep is a natural, periodic, and reversible state of rest in which consciousness is altered and sensory activity is decreased.

• In Ayurveda, Nidra (sleep) is considered one of the Trayopastambhas (three supporting pillars of life) alongside Ahara (diet) and Brahmacharya (celibacy).

• Proper sleep is essential for health, longevity, strength, enthusiasm, fertility, intelligence, and happiness.

DEFINITION OF SLEEP

• Modern Definition: Sleep is a state of rest in which the nervous system is relatively inactive, the eyes closed, postural muscles relaxed, and consciousness practically suspended

PHYSIOLOGY OF SLEEP :

पुण्डरीकेन सदृशं हृदयं स्यादधोमुखम् | जग्रतस्तद्विकसति स्वपतश्च निमीलति || ३४६|| 

सूक्ष्मावस्था स्मृतिर्निद्रा मनोवगिन्द्रियात्मनाम् | लोकादिसर्गप्रभवा तमोमूला तमोमयी ||३४७ || 

बाहुल्यात् तमसो रात्रौ निद्रा प्रायेण जायते | श्लेष्मावृतेषु स्रोतः सु श्रमादुपरतेषु च ।

इन्द्रियेषु स्वकर्मभ्यो निद्रा विशति देहिनम् || ३४८|| 

हृदयं चेतनास्थानमुक्तं सुश्रुत ! देहिनाम् | तमोऽभिभूते तस्मिंस्तु निद्रा विशति देहिनम् ||३४९|| 

निद्राहेतुस्तमः सत्वं बोधने हेतुरुच्यते । स्वभाव एव वा हेतु र्गरीयान्परिकीर्त्यते || ३५०|| 

करणानां तु वैगुण्ये तमसाभिप्रवर्धिते । अस्वपन्नपि भूतात्मा प्रसुप्त इव चोच्यते ॥ ३५९ ॥

सर्वेन्द्रियव्युपरत मनोनुपरतं यदा । विषयेभ्यस्तदा स्वप्नं नानारूपं प्रपश्यति ||३५२|| 

पूर्वदेहानुभूतांस्तु देहात्मा स्वपतः प्रभुः । रजोयुक्तेन मनसा गृह्णात्यर्थान् शुभाशुभान् ||३५३||

TYPES OF SLEEP

IN MODERN PHYSIOLOGY

• Sleep is broadly divided into two types:

  • Non-Rapid Eye Movement (NREM) Sleep

    • Also called slow-wave sleep.

    • Has four stages based on EEG: stages 1–4.

    • Associated with reduced physiological activities.

  • Rapid Eye Movement (REM) Sleep

    • Also known as paradoxical sleep or dreaming sleep.

    • EEG resembles that of an awake person.

    • Characterized by vivid dreams, rapid eye movements, muscle atonia.
      
      

IN AYURVEDA

• Nidra is of six types : 

  • Shleshma Sammarsaja Nidra – sleep caused by Kapha dominance.

  • Tamasika Nidra – sleep due to mental Tamas.

  • Manasija Nidra – caused by emotional factors like anxiety or depression.

  • Sharirika Nidra – due to physical exhaustion.

  • Vaishayi Nidra – induced by indulgence in sensual pleasures.

  • Agantuki Nidra – sleep due to external factors like drugs or trauma.

  • Swabhavika Nidra – physiological, natural sleep, essential for health.

    
    

PHYSIOLOGY OF SLEEP IN MODERN SCIENCE

• Controlled by Reticular Activating System (RAS) in the brainstem.

• Suprachiasmatic Nucleus (SCN) of the hypothalamus regulates the circadian rhythm.

• Neurotransmitters involved include:

  • Serotonin – initiates sleep.

  • Melatonin – released from the pineal gland, promotes sleep.

  • Gamma-Aminobutyric Acid (GABA) – induces and maintains sleep.

  • Acetylcholine – active during REM sleep.

• Sleep Cycle:

  • Lasts about 90 minutes.

  • Repeats 4–6 times per night.

  • Alternates between NREM and REM sleep.

    
    

PHYSIOLOGY OF SLEEP IN AYURVEDA

• Sleep occurs due to Kapha dominance and withdrawal of sense organs from their objects.

• When Manas, Indriyas, and Atma detach from Vishaya, sleep is naturally induced.
  
  

FUNCTIONS OF SLEEP

• Modern View

  • Restoration and repair of neural tissue.

  • Memory consolidation, especially in REM sleep.

  • Metabolic waste clearance from brain (glymphatic system).

  • Regulation of hormone secretion (e.g., growth hormone during deep sleep).

• Ayurvedic View

  • Maintains equilibrium of Dhatus.

  • Enhances Agni (digestive fire) and Ojas (immunity).

  • Rejuvenates body and mind.

    
    

DREAMS (SWAPNA)

MODERN UNDERSTANDING

• Dreams occur mainly during REM sleep.

• Serve in emotional processing and memory integration.

• Theories include:

  • Activation-synthesis theory – brain tries to make sense of random neural activity.

  • Information-processing theory – dreams help process and sort information.

• • Dreams may reflect past experiences, heard knowledge, desires, or even future events.

• Swapna is a sign of the health of Manovaha Srotas.

• Types of dreams described as auspicious or inauspicious depending on Dosha condition.

DOSHAS AND SLEEP

• Kapha predominance induces and maintains normal sleep.

• Pitta disturbance may cause interrupted sleep.

• Vata vitiation leads to insomnia or light sleep.

DISORDERS OF SLEEP

MODERN CLASSIFICATION

• Insomnia – inability to fall or stay asleep.

• Hypersomnia – excessive sleep.

• Sleep Apnea – obstructed breathing during sleep.

• Narcolepsy – sudden onset of sleep during the day.

• Parasomnias – abnormal behaviors during sleep (e.g., sleepwalking).
  
  

AYURVEDIC CORRELATES

• Alpanidra (less sleep) – due to Vata and Pitta vitiation.

• Atinidra (excessive sleep) – due to Kapha dominance.

• Nidranasha – equated with insomnia, treated using Medhya Rasayana, Snehana, Shirodhara, etc.

  
  

MANAGEMENT OF SLEEP DISTURBANCE

MODERN APPROACH

• Cognitive-behavioral therapy.

• Sleep hygiene practices.

• Pharmacological treatment (sedatives, melatonin).
  
  

AYURVEDIC APPROACH

• Snehapana, Abhyanga, Shirodhara, Takradhara, Nasya.

• Use of Medhya Rasayana like Brahmi, Mandukaparni, Ashwagandha.

• Dinacharya and Ritucharya practices to balance Doshas and improve sleep quality.