Classical documentation

Ashtanga Hridayam, Sutrasthana 1 opens with the definition of Ayurveda and immediately documents its eight branches. The same eight-branch system is documented in Charaka Samhita and Sushruta Samhita, with minor variations in nomenclature reflecting each text's primary domain.

Ashtanga Hridayam, Sutrasthana 1.5
Kayabala-graha-urdhvanga-shalya-dansra-jara-vrisham / Ashtau angani tasyahuh — The eight limbs: Kaya (internal medicine), Bala (paediatrics), Graha (exogenous conditions), Urdhvanga (above the clavicle), Shalya (surgery), Damstra (toxicology), Jara (rejuvenation), and Vrisha (reproductive health).

The eight branches

Kayachikitsa

काय चिकित्साInternal Medicine

The largest branch. Kaya = the body governed by Agni. Documents treatment of all systemic diseases through Agni, Dosha, Dhatu, and Mala. Primary text: Charaka Samhita.

Kaumarabhritya

कौमार भृत्यPaediatrics and Obstetrics

Encompasses conception to adolescence: Prasuti Tantra (obstetrics), Stanya (lactation), and paediatric medicine. Primary text: Kashyapa Samhita.

Shalya Tantra

शल्य तन्त्रSurgery

Documents over 300 surgical procedures, 120 instruments. Sushruta's rhinoplasty and cataract documentation are the oldest surgical records for these procedures in the world. Primary text: Sushruta Samhita.

Shalakya Tantra

शालाक्य तन्त्रENT and Ophthalmology

Treats conditions of the structures above the clavicle: ear, nose, throat, eye, and mouth. Documents 76 eye conditions, 28 ear conditions. Primary documentation: Ashtanga Hridayam, Uttarasthana.

Bhuta Vidya

भूत विद्याPsychiatry

Classical psychiatry and conditions with exogenous causes. Documents Unmada (major psychiatric conditions) and Apasmara (seizure conditions). Primary text: Charaka Samhita, Chikitsasthana.

Agada Tantra

अगद तन्त्रToxicology

Science of poisons and antidotes. Documents plant poisons, animal venoms, food incompatibilities, and environmental toxicology. Primary texts: Charaka Samhita and Sushruta Samhita, Kalpasthana.

Rasayana

रसायनRejuvenation

Rejuvenation, longevity, and optimisation of all biological functions. The longest chapter in Charaka Samhita. Documents Chyawanprash as the foundational formulation.

Vajikarana

वाजीकरणReproductive Health

Shukra (semen/reproductive tissue) enhancement, sexual capacity, and optimising reproductive potential. Primary text: Charaka Samhita, Chikitsasthana, Vajikarana chapter.

The integrated system

The eight branches share a common framework of Dosha, Dhatu, Agni, and Srotas, and a common diagnostic methodology. A surgeon (Shalya Tantra) uses the same constitutional assessment as an internist (Kayachikitsa). The specialisation is in target organ system and specific techniques — not in a separate theoretical framework.