[Means for knowledge of disease] Diseases could be diagnosed by studying their nidana (etiology), poorvarupa (premonitory symptoms), linga (sign and symptoms), upashaya (pacifying factors) and samprapti (pathogenesis).
[Definition of Linga (sign) and its synonyms] Sign and symptoms when fully manifested are called as linga. Linga, akruti, lakshana, chihna, samsthana, vyanjana and rupa are synonyms of linga.
[Definition of Upashaya (pacifying factors)] Medicines, diets and regimens that bring about relief either by acting directly on the cause of a disease or the disease itself or by producing such effects indirectly are termed upashaya (pacifying factors).