HLSC 3805U Chapter Notes - Chapter 3: Sexually Transmitted Infection, Waterborne Diseases, Horizontal Transmission
Disease is an interruption, cessation, or disorder of body functions, systems, or organs. Diseases arise from infections agents, inherent, weaknesses, lifestyle, or environmental stresses. the science and study of the causes of disease and their mode of operation is referred to as etiology. -> may involve direct transmission such as sexually transmitted diseases, a common vehicle such as waterborne, food-borne, or blood borne diseases, an airborne pathogen such as tb or vector- borne pathogen such as malaria. Non- communicable disease- not infectious, e. g. , heart disease, most forms of cancer, mental illness, and accidents. Diseases are classified as acute and chronic: acute- relatively severe disorder with sudden onset and short duration of symptoms, chronic less severe but of continuous duration, lating over long time periods if not a lifetime. Also be called incubation period. for chronic called latency period: stage of clinical disease begins when signs and symptoms are manifest, stage of recovery, disability, or death- reflects the expected prognosis.