Nidana Sthana (section on diagnosis) is about creating a strategy for diagnosing disease on the basis of history of causative factors and clinical examination. The study is comprehensive and is different from modern medical system to guide a physician to diagnose and treat disease with minimal use of laboratory, imaging and other tools. Ayurvedic diagnosis has two parts - the first being an evaluation of the self-healing capacity of the body which depends upon equilibrium of five components, namely doshas (body humors), agni (digestive and metabolic capacity), dhatu (body tissues), mala (waste) and psycho-spiritual state. Health is a state of equilibrium, whereas disease is a state of dis-equilibrium of any of these factors. According to swabhavoparam vada (theory of natural resolution), the resolution / destruction of the existing always happen naturally in the course of time. (Cha.Su.16/27) So the nature itself heals disequilibrium. This aspect of host defence mechanism is important to be assessed for knowing natural healing capacity of an individual. In the fourth chapter of Nidana Sthana, Prameha Nidana, the process of interaction between aggravating and pacifying factors to cause disease is described. If the host defense factors are stronger than aggravating ones, then the disease will not occur and vice versa. Therefore, before making diagnosis of a disease, it is important to examine patient first with emphasis on his prakriti (basic constitution), sara (quality of tissues) etc. Every person has a unique constitution and hence the same biological investigations cannot be precise to assess his health status completely. Personalized assessment is important to diagnose normal and abnormal state of the individual. The second part provides for a comprehensive knowledge of disease with its causative factors, premonitory signs and symptoms, clinical features, complications, aggravating and pacifying factors. Complete cure in curable diseases and management of palliable diseases can only be achieved after Nidana Parivarjana (removal of the cause). If the cause is removed, then half the treatment is done, because it stops progression of disease as well as helps the host to return to the normal state. Modern science focuses more on disease management after its complete manifestation, while Ayurveda emphasizes on identification of abnormality when it is in a very primitive stage, so as to prevent its further progression. The journey of a disease from the initial stage of accumulation of vitiating factors to complete manifestation of its symptoms is to be studied well for its complete knowledge. A disease can cause another disease is described with reference to Nidanarthakara roga. Upadrava (complications), Udarka (marks of disease after it is cured) are mentioned for knowing the cause-effect in relation to disease. Thus, this section on knowledge of diagnosis, points to two fold principles of management of disease in brief and to reverse the process by modifying the etiological, aggravating and pacifying factors of disease. The eight chapters of this section, focus upon eight disorders related with vitiated dosha acting on various dhatu to vitiate them. Any new disease, not mentioned in this text, should be studied with investigation of vitiated dosha and dushya (vitiated dhatu and other body components) first because all endogenous diseases start with vitiation of dosha. The enlisted causative factors elucidated in the detailed history of a patient’s diet, lifestyle, psychological frame and others direct the vitiation of a specific dosha. Then their status (increase or decrease) can be assessed based on the premonitory signs and clinical features, followed by evaluation of aggravating (anupashaya) and pacifying (upashaya) factors. The sequence of events in the pathogenesis of a disease is understood and accordingly treatment protocol is formulated.
- The first chapter, Jwara Nidana , introduces basic principles of diagnosis of a disease as well as the disease jwara with involvement of rasa dhatu as dushya.
- The second chapter, Raktapitta Nidana, deals with various pathologies related to rakta dhatu
- The third chapter, Gulma Nidana, deals with mamsa dhatu predominantly
- The fourth chapter, Prameha Nidana, involves meda dhatu predominantly
- The fifth chapter, Kushtha Nidana, involves seven dushyas
- The sixth chapter, Shosha Nidana, deals with the pathology of emaciation
- Lastly, the seventh, Unmada Nidana and the eighth chapters Apasmara Nidana explain psychiatric disorders like insanity and seizure disorders respectively.
Prajnaparadha (intellectual errors, or knowingly violating rules) is the main responsible factor for causation of all endogenous and exogenous diseases. Asatmenriyarthasamyoga (improper union of senses with their objects) and parinama(time) are other two causative factors . Therefore, this principle points that so called diseases of unknown etiology have a definite cause, that needs to be searched and removed for its management.