- Internal medicine (kaya chikitsa)
- Surgery (shalya)
- Ophthalmology and otorhinolaryngology (shalakya)
- Toxicology (agad tantra)
- Psychiatry (bhoot vidya)
- Pediatrics (kaumar bhritya)
- Gerontology (rasayana)
- Science of fertility (vajikarana)
The knowledge about all these eight divisions of Ayurveda was systemized with the origin of Ashtanga Ayurveda around 800-600 B.C. This Ashtanga Ayurveda must have served as the ground or basis on which the new knowledge regarding the eight divisions was formed.
The subjects of Ayurveda were recorded not only in the Vedas, but also in Aranyakas, Brahmanas and Upanishads. All the details were scattered all over the texts and lacked the structural presentation. The structural presentation of Ayurveda took place between 2 nd century B.C. and 10 th century A.D. These presentations were named Samhitas. The two most popular Samhitas are Charaka Samhita and Susrutha Samhita. Charaka Samhita is older than Susrutha Samhita. Charaka Samhita deals with kaya chikitsa i.e. general medicine and Susrutha Samhita deals mostly with shalaya i.e. surgery. Charaka Samhita is considered to be the compilation of the oldest Atreya Samhita. The third major presentation is known as the Ashtanga Hridaya and it is a concise version of works of both Charaka and Susrutha. These three treatises are still in use and are believed to be over 1,200 years old.
(published with permission in writing from:http://www.ayurvediccure.co.uk)


