Nidra (निद्रा)
Nidra (निद्रा) refers to the sleep. Sleep is not merely the state of reversible unconsciousness but according to the Ayurveda, sleep is that state of body, mind, senses and energy where the interaction between purush (पुरुषः) and loka (लोकम्) is suspended for some time and all the above components relax, rejuvenate and refresh the individual. Sleep is associated with health and wellbeing of body (शरीरम्), mind (मनः) and senses (इन्द्रियाणि). It has widespread effects on life od an Individual.
Trayopastambha (त्रयोपस्तंभाः)
Ayurveda mentions the concept of 3 supporting pillars of life. These are called as 3 upastambhas. It is stated that, strength, immunity, complexion and growth of any individual is dependent on well-regulated support of 3 factors namely Ahara (food), nidra (sleep) and observance of bramhacharya (celibacy/control of senses) (Cha. Su. 11/35). These are called supports or pillars of one’s Ayu or life. Thus, Nidra is said to be one of 3 supports of life which plays integral role in one’s health and wellness.
Utpatti of Nidra
Acharya Sushruta has stated that, Nidra originates from maya of devata Vishnu. Thus, nidra is said to be Vaishnavi. As per Hindu tradition, Brahma, Vishnu and Shiva are the 3 devatas which represent the 3 dimensions of cosmic energy, creation, sustenance and destruction respectively. In this, Vishnu devata sustains the creation and represents the eternal principle of preservation. Thus, with respect to the human body Vaishnavi Nidra is said to be the factor that sustains life and helps in energy preservation. Therefore while evaluating the energy dynamics of human body Ayurveda lays high emphasis on sleep disturbances of the individual.
Nidra and Triguna
Nidra is said to occur due to Tamas guna abundance in body while Satva guna abundance helps one to wake-up from sleep. Therefore, abundance of these gunas in surroundings during day & night cycle naturally one feels sleepy or awakened. Raja guna affects movements of manas which is the main component of sleep pathway and thus this disturbs the normal pattern of sleep.
Types of Nidra
Ayurveda literature described various types of sleep. These types are nothing but various causes that induce sleep in an individual. These are as below
Tamobhava
Abundance of Tamas guna leads to induction of sleep. Therefore, tamas excess could be the only causative factor for sleep in some individuals at some time and then such kind of sleep is identified as Tamobhava.
Shleshmasamudbhava
Dominance of kapha dosha in body induces sleep. Thus, excess kapha causes sleep it is called as shleshmasamudbhava.
Vyadhyanuvarti:
In some rogas, excess sleep is manifested as a symptom. In such cases the sleep is believed to be disease related.
Agantuki:
Sleep is also observed as an Arishta lakshana in certain cases. Such sleep along with some other symptoms indicates towards end of life.
Exhaustion of mind (Manas) due to its activities like overthinking or exhaustion of body from strenuous activities ultimately makes body, mind and senses incapable to perform further activities and the exhausted individual sleeps. Such kind of sleep resulting from exhaustion is included under this category.
Ratrisvabhavprabhava
Tamas guna dominance due to darkness is believed to be the natural status of night (Ratri). And due to dominance of tamas sleep is induced. This is the course of natural cycle of sleep. Thus sleep that is induced due to day and night cycle, at night, is included in this category.