Last verified: April 2026
Charaka Samhita
चरक संहिता — The compendium of Charaka
The most cited classical text in Ayurvedic internal medicine. Eight sections, 120 chapters, approximately 12,000 verses. The source for Tridosha theory, Prakriti classification, dietary guidelines, the doctrine of Agni, and the clinical management of diseases across the full range of internal medicine. If it is in this codex and it is about internal medicine, the source is almost certainly Charaka Samhita.
The first thing that distinguishes Charaka Samhita from what most people expect a medical text to be: it opens not with diseases, but with a definition of life. The first chapter of the first section asks what life is, what its components are, and what the purpose of medicine is in relation to it. The remedies come much later. The understanding comes first.
The text is named after Charaka — but Charaka did not write it. The original text, called Agnivesha Tantra, was composed by Agnivesha, a student of the physician Punarvasu Atreya at the ancient school of Takshashila. Charaka revised and expanded it, giving the text its current name. Centuries later, when 17 chapters were found to be missing, the physician Dridhabala reconstructed them from other sources. The text we read today is the product of at least three major hands across a span of roughly a thousand years.
What survived this process is remarkable: a systematic, internally consistent framework for understanding health and disease that covers physiology, psychology, pharmacology, diet, daily routine, seasonal routine, and clinical medicine in a single text. Modern BAMS students in India study Charaka Samhita as a core curriculum requirement. A practitioner who knows this text knows the foundation of the entire classical system.
What the eight sections cover
| Section (Sthana) | Name | Chapters | What it covers |
|---|---|---|---|
| 1 | Sutrasthana | 30 | Foundational principles — definition of Ayurveda, Tridosha, diet, drug classification, seasonal regimen, the purpose of medicine |
| 2 | Nidanasthana | 8 | Diagnosis — causative factors and pathogenesis of eight major conditions |
| 3 | Vimanasthana | 8 | Measurement and assessment — Prakriti, Rasa theory, physician training, epistemology |
| 4 | Sharirasthana | 8 | Anatomy and physiology — embryology, Prakriti at conception, the seven Dhatu, the sense organs |
| 5 | Indriyasthana | 12 | Prognosis — sensory signs that indicate the direction of a condition, including terminal prognosis |
| 6 | Chikitsasthana | 30 | Treatment — clinical management of specific conditions with herbs, formulations, and regimens. Partially reconstructed by Dridhabala. |
| 7 | Kalpasthana | 12 | Pharmacy — preparation of specific medicinal substances. Reconstructed by Dridhabala. |
| 8 | Siddhisthana | 12 | Success in treatment — primarily Panchakarma procedures and their clinical application |
The five core doctrines of Charaka Samhita
Five doctrines that appear in Charaka Samhita define the entire framework of classical Ayurvedic medicine. Every herb prescription, every dietary guideline, every clinical decision in the classical system flows from one or more of these.
1. Tridosha Siddhanta — The three-force doctrine
Sutrasthana Chapters 1, 12, and 17 document the three Doshas (Vata, Pitta, Kapha) as the three governing principles of all physiological function. Their natural proportion constitutes health. Their disturbance constitutes the origin of all disease. This doctrine underlies every clinical decision in the text.
2. Prakriti Pariksha — Constitutional examination
Vimanasthana and Sharirasthana document seven constitutional types (Prakriti) fixed at conception, and establish that all prescriptions must be adapted to individual constitution. The doctrine that makes Ayurvedic medicine inherently personalised rather than universal.
3. Agni Siddhanta — The doctrine of digestive fire
Chikitsasthana documents Agni (digestive and metabolic fire) as the central determinant of health. Sutrasthana 27.349 states: "Agni eva sarirasya ayusho moolam" — "Agni is the very root of life." The strength of Agni determines the quality of digestion, tissue formation, immunity, and the formation of Ojas. All treatment in Charaka ultimately aims at restoring appropriate Agni.
4. Shat Kriya Kala — Six stages of disease progression
Sutrasthana Chapter 17 and Vimanasthana document six stages through which every disease progresses: accumulation, aggravation, overflow, deposition, manifestation, and structural change. Treatment at Stage 1–2 requires only diet and lifestyle correction. The doctrine that makes preventive medicine the primary scope of Ayurveda.
5. Prayojanam — The dual purpose of the science
Sutrasthana 30.26 states the two purposes: maintaining the health of the healthy, and treating the diseases of the sick. The first purpose precedes the second — a statement that Ayurveda is primarily a system for healthy living and secondarily a therapeutic system.
The 50 Mahakashayas — herb classification groups
Sutrasthana Chapters 1–4 document the 50 Mahakashayas — fifty groups of ten herbs each, classified by therapeutic action. These groups are the primary classification system for herbs in internal medicine. Each group is named for its dominant action: Jivaniya (life-promoting), Balya (strength-building), Rasayana (rejuvenating), Deepaniya (digestive-stimulating), Pachana (digestive), Shothahara (anti-inflammatory), and so on.
Every herb mentioned in the herb pages of this codex is identified by its Mahakashaya membership from Sutrasthana, providing the classical basis for its documented indications. The 50 Mahakashayas also appear in the herb's classification section in the Ayurvedic Pharmacopoeia of India monographs.
Textual history and redaction
The transmission history of Charaka Samhita is documented in the text itself. The original composition is attributed to Agnivesha — one of six disciples of Punarvasu Atreya of the Atreya school (Atreya Sampradaya), the northern school of internal medicine centred at Takshashila (modern-day Pakistan/northwest India). The five other disciples — Bhela, Jatukarna, Parashara, Harita, and Ksharapani — each also composed Samhitas, though only the Bhela Samhita survives in fragmentary form.
The redaction by Charaka is referenced in Dridhabala's introductory verses in Chikitsasthana: "Charakena punardrshtam, punah samskritam uttamam" — "reviewed by Charaka and again excellently revised." Scholarly consensus, based on linguistic analysis, cross-references with Buddhist and Jain literature, and references to the text in Chinese Buddhist sources (Xuanzang, 7th century CE), places the Charaka redaction between approximately 100 BCE and 200 CE.
Dridhabala's completion of the final 17 chapters of Chikitsasthana (chapters 14–30) and all of Kalpasthana and Siddhisthana is documented in his own introductory verses: he states he reconstructed these from "other texts" (anyashastra) after the originals were lost. The most current scholarly consensus, based on stylistic analysis by P.V. Sharma and others, places Dridhabala's work at approximately 9th–10th century CE Kashmir.
The Atreya-Charaka school vs the Dhanvantari-Sushruta school
Classical Ayurvedic scholarship recognises two major schools with distinct but overlapping frameworks. The Atreya school — represented by Charaka Samhita — emphasises internal medicine, diet, regimen, and the Tridosha framework as the primary diagnostic and therapeutic tool. The Dhanvantari school — represented by Sushruta Samhita — emphasises surgery, wound management, anatomy, and the primacy of Tridosha in surgical prognosis.
The two schools disagree on several specific points: the classification of Doshas (Charaka counts three; Sushruta sometimes implies a fourth — Rakta), the primacy of specific herbs, and certain pharmacological classifications. These disagreements are documented in both texts, and Vagbhata's Ashtanga Hridayam represents a conscious attempt to synthesise both. This codex notes school-specific disagreements where they affect the documentation of specific herbs or formulations.
Charaka Samhita in modern Indian regulatory context
The Ministry of AYUSH recognises Charaka Samhita as a Schedule I classical text under the Drugs and Cosmetics Act, 1940. Formulations documented in Charaka Samhita — with their classical ingredients and preparation methods — may be manufactured and marketed without requiring separate clinical trials, provided they meet Ayurvedic Pharmacopoeia of India standards for quality and identity. This Schedule I status is the regulatory basis for the continued commercial production of classical formulations documented in this codex.