Nidra

The term ‘Nidra’ means sleep (SAT-J.3). It is a natural physiological process that occurs in all living beings usually during the nights. It is essential for resting the body and mind after the day-long exertion. Sleep (nidra) is equally essential like food (ahara) and following the path of ultimate reality (brahmacharya). These three are three sub-pillars of life. [Cha. Sa. Sutra Sthana 11/35]

Contributors

Section/Chapter	Sharira / Nidra
Authors	Deole Y.S.1, Anagha S.1, Resmi B.G.2
Reviewed by	Basisht G.1
Affiliations	1Charak Samhita Research, Training and Development Centre, I.P.G.T.& R.A., Jamnagar 2 Department of Kriya Sharir, Govt. Ayurveda College, Thiruvananthapuram, Kerala, India.
Correspondence email:	carakasamhita@gmail.com
Date of first publication:	June 25, 2021
DOI	In process

Importance of sleep in the preservation of health

Sleep is an important part of lifestyle. It is estimated that an average individual spends nearly one third part of life in sleeping. Sleep is a basic human need. It is essential for good health, good quality of life and performing well during the day. Sleep deprivation can lead to various physical effects like sleepiness, fatigue, hypertension. It can cause cognitive impairments like deterioration of performance, attention, and motivation; diminishment of mental concentration, intellectual capacity, and mental health complications. Inadequate rest impairs the ability to think, handle stress, maintain a healthy immune system, and moderate emotions.

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]

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]

This article deals with the physiology of sleep, its classification, and its importance in healthy and diseased conditions described in Ayurveda texts.

Etymology and derivation

The word is derived from the Sanskrit word root “Nidi kutsyaayaam” by adding the suffix “rak”. It means sleep, sleepiness, sloth, dream, shutting, budding state, dead, dull, drowsiness etc.

Synonyms

Shayanam, swapa, swapna/ swapnam, samvesha, tandra, supti, vaishnavi [Su. Sa. Sharira Sthana 4/33]

Physiology of sleep

When the mind and body are tired, kapha dosha and inertia (tamas guna) are increased in the body. In this state, the sensory organs are unable to function. This state leads to sleep (nidra). [Cha. Sa. Sutra Sthana 21/35] Inertia (tamas) is the prime factor responsible for sleep (nidra). [Su. Sa. Sharira Sthana 4/34]

The interplay of two significant processes regulates the sleep-wake system.

a) Process S is the homeostatic drive for sleep. It is regulated by the neurons found in the preoptic area of the hypothalamus of the brain. These neurons contain molecules that inhibit neuronal communication and turn off the arousal systems during sleep.

b) Process C promotes wakefulness and alertness. The circadian system regulates it. Wakefulness is generated by an ascending arousal system from the brainstem. This activates forebrain structures by transmitting sensory information to the cerebral cortex and activating the nerve cells to interpret and analyze the sensory inputs.

Through the synchronization of the circadian system, process C assists in keeping sleep-wakefulness cycles coordinated with environmental light-dark cycles.

Process S is similar to the functions of kapha dosha and tamas guna that promotes sleep. Process C is similar to functions of vata dosha and rajo guna that promotes wakefulness.

Role of the mental constitution:

The mental constitution of a person can influence natural sleep patterns variably.

a)In tamas guna predominant people, sleep occurs excessively during both the day and night.

b)In rajas guna predominant people, sleep is irregular and can occur at any time, day or night.

c)In sattva guna predominant people, sleep occurs at midnight only. [Su. Sa. Sharira Sthana 4/33,Dalhana]

Dreams (swapna)

The dreams are seen due to the association of the mind with rajo guna. It perceives both auspicious and inauspicious objects of senses based on previous experiences in the form of dreams. [Su.Sa.Sharira Sthana 4/36-37]

When the mind continues to cognize, the sleeping person experiences different kinds of dreams. The sense organs are not receptive to their perceptions in this state. [A.S. Sutra Sthana 9/21]

A dream is a conscious experience that occurs during sleep. Although it may happen in any sleep phase, it prevails during the desynchronized phase (REM type). Like any information consciously identified, a dream triggers a specific behavior, that we call an oneiric behavior. It comprises two types of identifiable manifestations:

a) Motor: These components are usually weak and poorly expressed movements during a dream.

b) Vegetative: Phasic increases heart rate, blood pressure, respiration, pupillary diameter, and metabolic adjustments, which are expressed more consistently during a dream, as they are during attentive wakefulness.

Types of sleep

Sleep is broadly classified into three types based on its fundamental cause.

a) Natural sleep (swabhaviki nidra): This occurs in a healthy individual as a natural process.

b) Abnormal sleep/insomnia (vaikariki nidra): The abnormal sleep occurs due to aggravated vata dosha and depleted state of kapha dosha. It is also caused due to various ailments of the mind and body. This is known as vaikariki nidra.

c) Sleep due to inertia (tamasi nidra): When channels carrying sensory perceptions are filled with excess inertia (tamo guna) and predominant kapha, it leads to “tamasi nidra”. This type is seen at the time of death. It is difficult to awaken the person in this state. [Su.Sa. Sharira Sthana 4/33, Dalhana]

There are two types of sleep based on electroencephalographic (EEG) observations during sleep.

a) Non-rapid eye-movement (NREM) sleep

b) Rapid eye-movement (REM) sleep.

NREM sleep is divided further into four stages based on variations in brain wave patterns, eye movements, and muscle tone. In the course of a period of sleep, NREM and REM sleep alternate cyclically. A normal sleep episode begins with a short period of NREM stage 1, progressing through stage 2, followed by stages 3 and 4, and finally to REM. The individuals do not remain in REM sleep throughout the night. The cycle between the stages of NREM and REM continues. NREM sleep constitutes about 75 -80% of the total duration of sleep, and REM sleep constitutes the remaining 20 – 25%. The function of cyclic change between these two types of sleep is not yet understood.

However, irregular cycling or absent sleep stages are associated with sleep disorders. E.g. Individuals with narcolepsy enter sleep directly into REM sleep instead of entering sleep through NREM.

There are seven types of sleep based on the causes of sleep.

1) Originated from inertia (tamobhava)

2) Originated from kapha (shleshmasmudbhava)

3) Due to mental exertion (mana shrama sambhava)

4) Due to physical exertion (sharira shrama sambhava)

5) Due to exogenous factors (agantuki)

6) Associated with diseases (vyadhyanuvartini)

7) Normal sleep at night (ratri swabhava prabhava) [Cha. Sa. Sutra Sthana 21/58]

The sleep patterns in the above types of sleep are yet to be explored through research studies.

Diagnosis of sleep disorders

Sleep is an important parameter to assess the health status of a person. Sleep patterns are affected during different disease conditions.

• Loss of sleep (nidra nasha) is due to aggravation of vata dosha [ A. Hr. Sutra Sthana 11/6]

• Decrease in sleep duration (alpa nidra) is due to aggravation of pitta dosha [ A. Hr. Sutra Sthana 11/7]

• Increase in sleep duration (atinidra) is due to aggravation of kapha dosha [A. Hr. Sutra Sthana 11/8]

In contemporary views, sleep disorders include the following conditions:

• Insomnia

• Sleep-related breathing disorders like sleep apnoea

• Central disorders of hypersomnolence

• Circadian rhythm sleep–wake disorders

• Parasomnias

• Sleep-related movement disorders and other sleep disorders.

As per Ayurveda, the clinical presentations of sleep disorders may be broadly classified into two types.

a) Excessive sleep (atinidra)

b) Loss of sleep/insomnia (anidra)

Causes of excessive sleep

Excess consumption of fats in the diet causes excess accumulation of fat (medas) and kapha dosha. This leads to obstruction in body channels, heaviness in the body and lethargy. This causes excessive sleep or hypersomnolence. [A. S. Sutra Sthana 9/30-33]

Narcolepsy is a chronic neurological disorder that affects the brain’s ability to control sleep-wake cycles. People with narcolepsy have excessive, uncontrollable daytime sleepiness. They may also suddenly fall asleep at any time, during any kind of activity. The exact cause of narcolepsy is unknown in contemporary sciences. People with type 1 narcolepsy have low levels of the chemical hypocretin, which is an important neurochemical that regulates wakefulness and REM sleep.The relation between high-fat diet and narcolepsy needs further research.

Causes of insomnia

• Emotional states of fear, worry, anger, happiness, grief, anxiety

• Excessive smoking, exercise, fasting, exertion, sexual intercourse

• Excessive hunger, excessive intake of dry food

• Lapse of the standard sleeping time and habit

• Other mechanical factors like uncomfortable bed, atmosphere etc.

• Increased sattva guna and decreased tamas

• Old age

• Excess administration of procedures like therapeutic purgation (virechana), emesis ([vamana]]), nasal errhines (nasya), blood-letting (raktamokshana)

• Vata dosha predominant diseases, vata dosha dominance in basic body constitution (prakriti), aggravation of vata / vata along with pitta in the body due to any cause[Cha.Sa.Sutra Sthana21/55-57], [A. S. Sutra Sthana 9/34-36]

Research shows an increased prevalence of insomnia in women and older adults. In women, insomnia is more prevalent during menarche and menopause.Comorbid medical disorders, psychiatric disorders, and night duties or rotating shifts are significant risks for insomnia.

Clinical features of insomnia

Loss of sleep causes body ache, heaviness in the head, frequent yawning, stiffness, tiredness, giddiness, impaired digestion, stupor, and other vata predominant diseases. [A.S. Sutra Sthana 9/37] Suppression of natural sleep urge causes frequent yawning, body ache, stupor, diseases of head, and heaviness of eyes. [Cha. Sa. Sutra Sthana 7/23]

The persons with insomnia can develop the conditions causing hypoxemia and dyspnoea, gastroesophageal reflux disease, pain conditions, and neurodegenerative diseases. Among the primary sleep disorders, restless legs syndrome (RLS), periodic limb movement disorders (PLMD), and sleep-related breathing disorders (snoring, dyspnoea, sleep apnoea) often present with an insomnia symptom. Research shows a relationship between inadequate sleep and medical conditions like hypertension, obesity and type-2 diabetes, cardiovascular disease and arrhythmias,mood disorders,neurodegeneration and dementia,and impaired immune functioning.

Untimely sleep (akala nidra)

Excess sleep during daytime is contraindicated in a healthy person. It provokes three dosha and can cause many ailments such as cough, respiratory discomforts, rhinitis, heaviness of head, body pain, anorexia, fever, impaired digestive power etc. [Su.Sa. Sharira Sthana 4/38]

Diseases of head, giddiness, disorientation, obstruction in body channels, hampered digestion, edema, nausea, nasal discharge, pain in one side of head, itching, pain and eruptions over skin, stupor, throat diseases, augmented activity of poisons are the untoward effects of improper and untimely sleep. [A.S. Sutra Sthana 9/30-33]

The International Classification of Sleep Disorders (ICSD-2) includes “excessive daytime sleepiness” (EDS) as an essential feature for three diagnostic categories: narcolepsy, hypersomnia and behaviourally induced insufficient sleep syndrome. It is also associated with various diseases, including psychiatric and neurological disorders, pulmonary and cardiac conditions.

Indications of day time sleep

Though day sleep is contraindicated in all seasons, it can be advised in certain conditions to maintain the equilibrium of dosha in health.

It is advised in the summer season as the duration of the night is reduced. It is indicated in those who have exerted due to activities like singing, studying, alcohol consumption, copulation, purification procedures, strenuous work, and walking. The persons suffering from indigestion, external injuries and emaciation, excessive thirst, loose bowels, colicky pain, respiratory ailments, exhausted by a long journey, suffering from insanity or emotional outbursts, aged persons and children can sleep during the day. This helps to maintain the equilibrium of tissues (dhatu), and endow strength in such conditions. [Cha. Sa. Sutra Sthana 21/39-42]

Day sleep is especially advised for those suffering from severe thirst, colic pain, hiccups, and diarrhoea. [Su. Sa. Sharira Sthana 4/48]

Contraindications of day sleep

Day sleep is prohibited in all seasons except the summer season and above conditions. It vitiates kapha and pitta dosha. Obese persons, those habituated to fatty diet, kapha prakriti individuals, those suffering from kapha predominant diseases and cumulative toxins (dushi visha) should not sleep during the day. It can result in headaches, body pain, heaviness of the body, loss of appetite.[Cha. Sa. Sutra Sthana 21/44-47]

Duration of day time sleep:

Hungry persons or during starvation or fasting, in a decreased state of body components like fat (meda dhatu), sweat (sweda), kapha, rasa and rakta can sleep for 48 minutes (one muhurta) during daytime. Those who did not sleep during the night can sleep in the daytime. The duration of sleep shall be half the time of their night vigil. [Su. Sa. Sharira Sthana 4/38] This can help to maintain the biological rhythm of dosha and other body components.

Drowsiness (Tandra)

Tandra is a state similar to sleep. Aggravated kapha dosha is directed upwards in head by the vata dosha. This slows down the blood circulation to the head and leads to a state of loss of sensation and severe delusions. This state is called as “tandra”.[ A.S. Sutra Sthana 9/38-39]

In this state, the sense organs are non-receptive. The person feels sleepy with the heaviness of the body, excess yawning and exhaustion. [Su. Sa. Sharira Sthana 4/49] The eyes are wide open, eye-balls rolled in, dilated pupils, the outflow of tears and deranged eye lashes are seen in this condition. [A. S. Sutra Sthana 9/38-39]

Management of sleep disorders

Insomnia and hypersomnolence are managed by different therapeutic modalities.

Measures to improve sleep in insomnia

Diet promoting sleep:

• Meat soup of domestic, marshy and aquatic animals, burrow dwelling animals and gallinaceous birds

• Rice with curd, milk, and fatty substances

• “Shali” type of rice, wheat, food made of grain flour processed with sugarcane products

• Alcoholic beverages (madya)

• Sweet and unctuous substances with milk and meat soup

• Consumption of grapes, sugar and sugarcane during night

Activities/procedures

• Massage (body kneading and rubbing)

• Unction

• Bath

• Oil application over head

• Instilling nourishing substances in eyes

• Application of soothing paste overhead and face

Psychological measures

• Measures promoting pleasant state of mind

• pleasing smell or aroma

• pleasing sound or soothing music

• soft and well-spread bed

• cosy dwelling

• proper sleeping time

[Cha. Sa. Sutra Sthana 21/52-54][Su.Sa.Sharira Sthana 4/43-46]

Measures to control excess sleep or hypersomnolence

• Therapeutic emesis (vamana) and other purification therapies (panchakarma)

• Fasting (langhana)

• Blood-letting (rakta mokshana)

• Involvement in mental activities [Su. Sa. Sharira Sthana 4/47]

Night vigil as a therapeutic measure

Night vigil has therapeutic efficacy in treatment. It is indicated in conditions of aggravated kapha dosha, fat (meda dhatu), poisoning (visha) [Su. Sa. Sharira Sthana 4/48] and throat ailments. [A. S. Sutra Sthana 9/29]

Current researches

In the conventional management of insomnia, non-benzodiazepine hypnotics are the first line pharmacotherapeutic agents, followed by benzodiazepines, amitriptyline and antihistamines.

Research works on insomnia

Various research studies have shown the efficacy of herbal medications in the management of insomnia. The details of some of the herbal medications with proven efficacy and safety through clinical trials are given in the table.

Table 1: Researched formulations in management of insomnia

Compound/ single drug	Ingredients	Dose/duration/ vehicle
Mamsyadi ghrita	Ghee processed with Nardostachys jatamansi(jatamamsi), Convulvulus pluricaulis (shankhapushpi), Withania somnifera(ashwagandha),Valeriana wallichii (tagara)	20 g twice a day orally with luke warm water for 6 weeks.
Tagaradi Kwatha	Nardostachys jatamansi (jatamamsi), Convulvulus pluricaulis (shankhapushpi), Withania somnifera (ashwagandha), Valeriana wallichii (tagara), Bacopa monnieri (brahmi),Vitis vinifera (draksha), Picrorhiza kurrooa (katuki), Hedyotis corymbosa (parpataka), Aegle marmelos(bilwa),Premna Serratifolia/integrifolia(agnimantha), Oroxylum indicum(shyonaka), Stereospermum suaveolens(patala), Gmelina arborea (gambhari), Solanum indicum(bruhati), Solanum xanthocarpum(kantakari),Desmodium gangeticum(shalaparni), Uraria picta(prushniparni), Tribulus terrestris(gokshura), Cyperus rotundus (musta), Pterocarpus santalinus (raktachandana), Cassia fistula(aragwadha)	40gm/day (In two divided doses each of 20 gms) in decoction form for 6 weeks
Parasikayavani capsule	Hyoscyamus niger (parasikayavani)-1/4 part and Nardostachys jatamansi (Jatamansi)-1 part, triturated 7 times in juice of Convulvulus pluricaulis (shankhapushpi) and 7 times in juice of Benincasa hispida (kushmanda)	5 Capsules, with luke warm water, at bed time, for 1 month.
Apamargadi vati	Achyranthes aspera (apamarga), Asteracantha longifolia (kokilaksha), Perstrophe bicalyculata Linn (kakajangha), Psoralia corylifolia (bakuchi)	1 gm trice a day, with buffalo milk, for 8 weeks.
Powder of root of Piper longum(pippali moola)	--	2 gm twice a day with jaggery (guda), after food , for 4 weeks
Leaf powder of Nardostachys jatamansi (Jatamansi)	--	3 gm powder with honey (5g), ½ hour before bed time for 4 weeks.
Powder of Citrus medica Linn(beejapura) leaves	--	3 gm powder with honey (5g), ½ hour before bed time for 4 weeks
Insomrid tablet	Withania somnifera (ashwagandha), Rauvolfia serpentina (sarpagandha), Nardostachys jatamansi (jatamamsi), Valeriana wallichii (tagara), Hyoscyamus niger (parasika yavani)	2 tab (each of 500 mg) in the morning after breakfast and night after the dinner with luke warm milk for 30 days.

Therapeutic procedures:

Apart from oral medications, the local procedures like pouring of the medicated liquid on the forehead (shirodhara), application of medicated oil on head (shiro abhyanga and shiro pichu) have shown significant results in the management of insomnia.

The liquids used for Shirodhara in clinical trials are as follow:

• Oil processed with Nardostachys jatamansi (jatamamsi taila)

• Decoction of 10 medicinal plant roots known as “Dashamoola” [Aegle marmelos(bilwa),Premna Serratifolia/integrifolia(agnimantha), Oroxylum Indicum(shyonaka), Stereospermum Suaveolens(patala), Gmelina Arborea(gambhari), Solanum Indicum(bruhati), Solanum Xanthocarpum(kantakari),Desmodium gangeticum(shalaparni), Uraria Picta(prushniparni), Tribulus Terrestris(gokshura)]

• Buffalo’s milk (mahisha dugdha)

• Ksheerabala taila

The duration of the procedure done in the clinical trials ranges from 30-45 minutes daily for 2-3 weeks, preferably in morning. The temperature range of liquid was 38-40 degree Celsius. A clinical trial showed efficacy of lukewarm water as equal to medicated oil in shirodhara procedure. The combined therapy with oral medication and local procedures shows appreciable results in the management of insomnia.

Theses works

1) Nirmal Dhamini A (2004): Role Manasa Bhavas in Anidra and its management with certain indigenous drugs and Shiro-Dhara, Department of Kayachikitsa, IPGT &RA, Jamnagar.

2) Anil Kumar Singh (2007): A Clinical Study Of Manasika Bhavas In Anidra W.S.R To Stress Induced Chronic Insomnia And Its Management With Mamsyadi Ghrita And Dashamula Kwatha Shirodhara, Department of Kayachikitsa, IPGT &RA, Jamnagar.

3) Bina H Vansh(2008) : clinical study on Mansika Bhavas in Anidra w.s.r. to stress induced insomnia & its management with Tagaradi Kwatha & Mahishi Dugdha Shirodhara, Department of Kayachikitsa, IPGT &RA, Jamnagar.

4) M P S K R Muthugala (2013): Evaluation of Parasikayavanyadi Capsule in the management of Anidra w.s.r. to Insomnia, Department of Kayachikitsa, IPGT &RA, Jamnagar.

5) Chinmay P Joshi(2013) : Comparative study on the effect of Sneha Dhara & Jala Dhara in Anidra (Insomnia), Department of Panchakarma, IPGT &RA, Jamnagar.

6) Hapaliya Sunilkumar Babulal (2014): A Clinico Comparative Study of Madhukadi Taila Shiropichu and Pippalimoola Churna in the Management of Anidra with special reference to Insomnia, Department of Panchakarma, IPGT &RA, Jamnagar.

7) Kalpesh panara (2014): A pharmaco clinical evaluation of Beejapoorapatra (leave of citrus medica linn.) W.S.R to insomnia, Department of Dravyaguna, IPGT &RA, Jamnagar.

8) Krutika joshi (2014) : A pharmaco clinical evaluation of Pippalimoola (root of piper longum) W.S.R to insomnia, Department of Dravyaguna, IPGT &RA, Jamnagar.

9) Mithilesh Kumar Sah (2015): Study On Concept Of Nidra (Sleep) And Diva-Swapna With Applied Aspect Of Snigdham Praswapnam Diva, Department of Basic Principles, IPGT &RA, Jamnagar.

10) Rawal Priyanka Manipal (2017) : A Critical Study On Trividha Aushadha And Applied Aspect Of Ahitebhyo Arthebhyo Manonigraha In The Management Of Anidra, Department of Basic Principles, IPGT &RA, Jamnagar.

11) Goti Keval Kalubhai (2017): Pharmaco-Clinical Evaluation Of Nidrajanana Karma(Sedative Activity) Of Bijapuradi Yoga W.S.R. To Anidra( Insomnia), Department of Dravyaguna, IPGT &RA, Jamnagar.

12) Parth K Barad(2017): Pharmacognostical-Clinical Study Of Ikshurak Mool Kwath On Anidra W.S.R. To Insomnia, Department of Dravyaguna, IPGT &RA, Jamnagar.

References