The course of disease without any intervention is the definition of

Answer: a) Natural history of disease (PARK 23rd ED, P-35)Natural history of disease signifies the way in which a disease evolves over time from the earliest stage of its prepathogenesis phase to its termination as recovery, disability or death, in the absence of treatment or prevention.NATURAL HISTORY OF DISEASEDisease processPre-pathogenesis phase Pathogenesis phaseDisease agent has not entered man After the entry of agent into the (man in the midst of disease or man susceptible human host exposed to the risk of disease) Outcome may be - recovery, disability orInteraction between agent, host & death environment required to initiate diseaseprocess in manLevels of preventionPrimary prevention Secondary preventionTertiary preventionModes of interventionHealth promotion Early diagnosisSpecific protection & treatmentDisability limitationRehabilitation