Disease
A disease is an abnormal condition that impairs an organism’s normal structure or function and produces characteristic signs or symptoms.
Health: A state of physical, mental, and social well-being, not merely the absence of disease. Disease is commonly defined by impairment relative to health, though the boundary is not always clear.
Etiology: The cause or origin of a disease or other condition. Etiology identifies what initiates a disease.
Diagnosis: The identification of a disease or condition from evidence such as symptoms, signs, and tests. Diagnosis determines which disease best accounts for a person's findings.
Disorder: A disturbance in the structure or function of the body or mind. The term often overlaps with disease but can signal different clinical or social conventions.
Morbidity: Illness, complications, or other adverse health effects within an individual or population. Morbidity measures the burden of disease beyond death.
Pathology: The study of the causes and effects of disease, including structural and functional changes in organisms. It examines the changes that make a condition a disease.
Pathogenesis: The biological process by which a disease develops and progresses. It traces the steps between a cause and the resulting disease.
Differential diagnosis: A structured list of possible explanations for a patient's signs and symptoms. Similar manifestations can arise from different diseases, requiring comparison.
Disability: A long-term physical, mental, intellectual, or sensory impairment that can limit participation through interaction with barriers. Disability concerns functioning and barriers, not simply the presence of disease.
Mortality: The occurrence of death in a population over a specified period. Mortality captures the most severe population-level outcome of disease.