what is the disease?
Definition of disease. 1  1 obsolete : trouble. 2  2 : a condition of the living animal or plant body or of one of its parts that impairs normal functioning and is typically manifested by distinguishing signs and symptoms : sickness, malady infectious diseases a rare genetic disease heart disease.
A disease is a particular abnormal condition, a disorder of a structure or function, that affects part or all of an organism. The causal study of disease is called pathology. Disease is often construed as a medical condition associated with specific symptoms and signs.n humans, disease is often used more broadly to refer to any condition that causes pain, dysfunction, distress, social problems, or death to the person afflicted, or similar problems for those in contact with the person.