Aṣṭāṅga Āyurveda means eight branches of Āyurveda. Ācāryas arranged the eight branches based on their areas of expertise.

तस्यायुर्वेदस्याङ्गान्यष्टौ; तद्यथा- कायचिककत्सा, शालाक्यं, शल्यापहतृृकं,

चर्वषगरर्वैरोचधकप्रशमनं, भूतचर्वद्या, कौमारभृत्यकं, रसायनं, र्वाजीकरणचमचत || Ca.Sū.30/28 ||

Ācārya Caraka classified as Kāyacikitsā, Śālākya, Śalya, Visa (Agada Tantra), Bhūta vidyā, Kaumārabhṛtya, Rasāyana, and Vājīkaraṇa

तद्यथा- शल्यं, शालाक्यं, कायचिककत्सा, भूतचर्वद्या, कौमारभृत्यम्, अगदतन्रं,

रसायनतन्रं, र्वाजीकरणतन्रचमचत || Su.Sū. 1/7||

Ācārya Suśruta classified as Śalya, Śālākya, Kāyacikitsā, Bhūta vidyā, Kaumārabhṛtya, Agada tantra, Rasāyana tantra, and Vājīkaraṇa tantra.

कायबालग्रहोर्धर्वाृङ्गशल्यदंष्ट्राजरा र्वृषैैः|

गतमष्टाङ्गतांपुण्यंबुबुधेयंचपतामहैः ||A.S.Sū.1/3||

कायबालग्रहोर्धर्वाृङ्गशल्यदंष्ट्राजरा र्वृषान् ||५||

अष्टार्वङ्गाचन तस्याहुचिककत्सा येषु संचिता| A.H.Sū.1/5-6||

Whereas Ācārya Vāgbhaṭa is classified as Kāya (Kāyacikitsā), Bāla (Kaumāra bhṛtya), Graha (Bhūta vidyā), Ūrdhvāṅga (Śālākya tantra), Śalya tantra, Daṃṣṭrā (Agada tantra), Jarā (Rasāyana), and Vṛṣā (Vājīkaraṇa) and documented in his Saṃhitā in accordance with these classifications

In modern science, these branches may be understand as follows

• Kāyacikitsā – General medicine / Internal medicine
• Kaumārabhṛtya – Pediatrics
• Graha – Psychiatry
• Śalya – Surgery
• Śālākya – ENT and Ophthalmology
• Viṣa – Toxicology
• Rasāyana – Geriatrics / Rejuvenation therapy
• Vājīkaraṇa – Aphrodisiac therapy