Ayurveda is old enough that its beginnings are a matter of inference rather than record. What survives is the literature, and the literature is remarkably specific.
The word itself joins ayus, life, and veda, knowledge. Its earliest traces sit in the Vedic corpus, most visibly the Atharvaveda, where plants, seasons and bodily conditions are already being catalogued together. What we now recognise as Ayurveda proper emerges later, as a structured medical system with its own vocabulary, method and canon.
The three great texts
Three works form what is traditionally called the Brihat Trayi, the great triad.
The Charaka Samhita is the text of internal medicine: diagnosis, regimen, diet, conduct, and the physician's obligations. The Sushruta Samhita is the surgical text, and its descriptions of instruments, incisions and reconstructive procedures are startling to read at any distance. The Ashtanga Hridaya, compiled by Vagbhata, is the later synthesis, condensed and orderly, and it is the version most students still learn from.
Together they describe eight branches, which is what ashtanga means. Internal medicine, surgery, the treatment of the head and neck, paediatrics, toxicology, psychiatry, rejuvenation and virility. It was a complete system with a complete curriculum.
Health as timing
The part of Ayurveda that has aged best is not any particular remedy. It is the insistence that health is a matter of timing.
Two ideas carry this. Dinacharya is the daily regimen: what is done at which hour, from waking to sleeping. Ritucharya is the seasonal regimen: what changes as the year turns. Neither is about treating illness. Both are about ordering an ordinary day so that illness has less to work with.
The tradition did not separate the medicine from the hour at which it was taken.
What it says about sleep
Charaka is direct about sleep. He places nidra among the three upastambha, the sub-pillars that support life, alongside ahara, food, and brahmacharya, disciplined conduct. The reference is Sutrasthana 11.35, and it is a striking piece of prioritisation for a text of that age.
He goes further in the twenty-first chapter, where proper sleep is tied to happiness, nourishment, strength and understanding, and improper sleep to their loss. Sleep, in other words, was not treated as the absence of activity. It was treated as one of the three things holding a life up.
Interruption, and return
Ayurveda's institutional life was disrupted under colonial administration, when state recognition and funding moved decisively towards European medicine. The tradition continued in households and in regional lineages, but it lost its standing.
Its return has been gradual and then rapid. India created a dedicated Ministry of AYUSH in 2014, giving Ayurveda, Yoga, Unani, Siddha and Homoeopathy their own administrative home. In 2022 the World Health Organization established its Global Centre for Traditional Medicine at Jamnagar in Gujarat, the first of its kind anywhere.
What we take from it
ZANAR is not an Ayurvedic pharmacy and Nidravati Vidhana is not an Ayurvedic medicine. What we take from this inheritance is a way of thinking rather than a formula: the choice of ingredient, the manner of preparation, and the hour at which a thing is best received.
That last idea is as old as the canon and still, in most modern evenings, entirely unused.
Nidravati Vidhana is an aromatherapy preparation for the inhalation of vapour only. It is not a medicine, and no part of it is to be ingested.