Disease is a set of signs and specific symptoms that affect a living being, changing your state normal of health. The word is of Latin origin, in which "infirmity” means “pain, suffering”.
In general, the disease is characterized as lack of health, a state that, when it affects an individual, causes disturbances in physical and mental functions. It can be caused by exogenous factors (external, from the environment) or endogenous (internal, from the organism itself).
Different sciences are dedicated to the study of diseases, including: pathology studies diseases in general, related to medicine and other areas; medical science studies the diseases of humans; plant pathology analyzes diseases that affect plants; veterinary medicine studies the pathological manifestations in animals.
In general, when examining a patient, the professional observes the signs and symptoms and associates them with a particular disease, requests several tests and from the results informs a diagnosis, which will be the basis for the treatment.
Depending on the context, some concepts, such as abnormality, disorder, pathology, disturbance, etc., are used synonymously with disease.
In the figurative sense, illness is an addiction or a mania, considered as an imbalance. For example: The impulse to buy shoes has become a disease.