Causes of disease (nidana)

The introduction says nidāna is the principal basis of medicine; the word literally means 'root cause', but by established usage it is used in the sense of examining (diagnosing) disease.

The publisher's note says that disease coming to the body depends on karma, but that by the use of the pure medicines described in the book even asātā (painful experience) turns into sātā (ease) and the disease subsides.

The introduction gives three causes of disease: unsuitable contact of the senses with their objects (asātmyendriyārtha-saṁyoga), errors of judgement (prajñāparādha) and the effect of time (pariṇāma or kāla). The first produces particular states through contact that act on the three dhātus and the mind; prajñāparādha acts first on the mind and then on the body; time likewise acts on body and mind. The doṣas so produced pass through accumulation, aggravation, spread and lodging in a site (caya, prakopa, prasara, sthāna-saṁśraya), giving rise to inflammation (saṁrambha), swelling, abscess, ulcer and putrefaction. These states of the doṣas are called the regular causes of disease, the union of doṣa and dūṣya the irregular cause, and poison, gara and living poisonous germs the instrumental (nimitta) causes.

It says modern medicine claims certainty about the causes of disease since the rise of the study of germs, but the mere presence of a germ does not make it the cause, because many healthy people carry germs without the disease. The germ is like a seed that grows only on favourable soil, and that favourable condition is a body vitiated by the doṣas; on unfavourable ground, like seed on barren land, it can neither grow nor cause disease. Even in terrible diseases like cholera and plague only a few people fall ill, so the germ is one instrumental cause among others.

It says that the deficient, wrong or excessive conjunction of time, sense objects and actions (kāla, artha, karma), that is, of the three causes above, unbalances the body-sustaining dhātus and produces doṣas, and through the accumulation and aggravation of the doṣas disease arises; it calls this Ayurveda's original (abhinava) theory of the origin of disease, of great use in treatment. A footnote quotes Aṣṭāṅgahṛdaya Sūtra 1 that the deficient, wrong and excessive conjunction of time, objects and actions is the one cause of disease, and their right conjunction the one cause of health.

According to the editor, the author names the karma that brings pain (asātāvedanīya karma) as the main cause of ill health and imbalance of vāta, pitta and kapha as an external cause. Likewise the main causes of a disease subsiding are the early fruition (udīraṇā) of that karma, the rise of the karma that brings ease (sātā) and the practice of dharma, while the external causes are treatment suited to the disease and the favourability of substance, place, time and fortune.

All disorders of the body are said to have causes, which must be judged by distinguishing primary from secondary; the primary cause of disease is one's own previously done karma, and all other causes are its qualifiers, that is, secondary instrumental causes.

Diseases are said not to arise from the anger of the elements such as earth, nor from aggravation of the doshas, nor from a bad year or the anger of planets such as Mars, but only from the rise (udaya) and udīraṇā of karma.

Diseases are said to arise from the rise of sin; sin and dharma are opposed to each other, so where dharma is present sin is destroyed, and the patient should therefore stay devoted to dharma.

The text holds that no effect, including disease, arises without causes of two kinds, internal and external, so the physician treats every disorder after knowing its dosha sequence.

The text says that by their own nature some major diseases arise quickly from the doshas and others late, as seeds given all favourable conditions still sprout some early and some late.

Six kinds of causes of disease are named: vata, pitta, kapha, blood (rakta), all three doshas together (sannipata) and external injury (abhighata).

The text cites Charaka that a creature is born of karma and its diseases are born of karma, and that without karma there is no birth of diseases or of the person; it uses this, with its account of diseases that arose from killing, to argue that meat cannot cure them.

Quoting Charaka, the translation says every creature is born of karma and so are its diseases; as diseases do not arise without karma, neither does a person; and the nidana (nimitta) science too is said to hold that meat cannot counter diseases born of sin.

Footnotes on this quotation give its source as Charaka, Sutrasthana (the chapter and verse digits are garbled), the variant मतो, and the reading रोगाणां of the printed book.