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.

• Ayurvedic View:
  निद्रायत्तं सुखं दुःखं पोषः कृशता बलम्।
  वीर्यं ज्ञानं जीवनं च निद्रा हि नृणां ध्रुवम्॥
  (A.Hr. Su.7/63)

  • Meaning: Happiness and misery, nourishment and emaciation, strength and weakness, virility, knowledge, and life depend on sleep.

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 as mentioned in Charaka Samhita:
  श्लेष्मसम्मर्शजा चैव तामसी मानसस्मृता।
  शारीरी वैषयी चैव आगन्तुकी च सप्तमी॥
  (Ca.Su.21/57)

  • 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.
  मनःस्वस्थेन्द्रियाणां च सन्निपाते विशुद्धये।
  विषयेभ्यो निवृत्तेषु स्वप्नकालोऽभिजायते॥
  (A.Hr. Su.19/1)

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.

AYURVEDIC UNDERSTANDING

• Dreams are the result of subtle impressions (Samskaras) on the Manas and Atma.
  स्वप्नो दृष्टमनुप्राप्तं श्रुतं यच्च स्मृतं तथा।
  भविष्यं च तथा स्वप्नो लक्षणं तद्विचक्षणैः॥
  (A.Hr. Su.19/4)

  • 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.