It is called disease the process and the phase that living beings go through when they suffer a condition that threatens their well-being by modify its ontological condition of health. This situation can be triggered by multiple reasons, be they of character intrinsic or extrinsic to the body with evidence of disease. These triggers are known under the name of noxas (from the Greek nósos).

The term comes from the Latin infirmities what does it mean “Lacking in firmness” and it consists of a process that happens to a living being and alters its normal state of health.


There are different types of diseases.

What is meant by illness

In everyday language, illness is understood as an opposite idea to the concept of health: it is that which causes an alteration or breaks the harmony in an individual, be it on a molecular, corporal, mental, emotional or spiritual scale.

Given the difficulty of defining specifically what a disease is (since each individual does it according to their own experiences), there are several concepts that can be used, according to the context, as a synonym: pathology, disease, suffering, abnormality, disorder, disorder, imbalance and disturbance, among others.

There are different sciences that are responsible for studying, analyzing and fighting diseases. Phytopathology, for example, is dedicated to analyzing diseases that affect plants and other botanical genera. The pathologies to which animals are vulnerable, on the other hand, are addressed by the veterinarian. Medical science, on the other hand, deals with the diseases of humans.

In this way, the various branches of medicine investigate the peculiarities inherent to each creature, its symptoms and the consequences that they entail, taking into account the morphophysiological evidence that it leaves in the biology of the diseased organism.

Classification according to its origin

The causes of a disease can be many, some related to external agents and others internal, these factors are called noxas, which comes from the Greek nósos which means disease or health condition.

High temperature

Fever can be a sign of an illness.

Some meanings of the term, but related to the definition given above are:

Bacterial diseases: those produced by a known bacterium that develops known symptoms.

Viral diseases: Those that are produced by a virus whose consequences are fairly predictable.

Venereal diseases: Those sexually transmitted diseases that produce more or less serious symptoms and consequences.

Respiratory diseases: Those that affect the organs belonging to the respiratory system, responsible for lavishing oxygen to the body and eliminating carbon dioxide.

Mental or psychological illnesses: They are those that affect mental health, that prevent the normal functioning of an individual in their emotional aspect.

Other definitions of disease

As defined by the World Health Organization, the term health implies the perfect well-being at the physical, mental and social of an individual, while disease is the presence of a disease or specific condition. An individual with only one condition is lacking in health.

For him Teide Medical Dictionary A disease is called the set of structural morphological alterations that occur in the body as a result of an internal or external morbidity agent, against which the body does not have the ability to oppose or does not manage to face it with sufficient force.

For his part, Terminological Dictionary of Medical Sciences collects that a disease is the loss of health, that is, a deviation from the physiological state of generally known etiology, which occurs through specific symptoms and whose maturation is predictable.

The vision of homeopathy

The homeopathy defines a disease as the acute exacerbation of internal disharmony, a way (the only possible) that the body has to react to a change in its energy.

Ultimately, a disease is a alteration of the physiological state in some of the parts of the body that manifests itself through known specific symptoms whose prediction is more or less predictable. In the event that there are symptoms but it is not known which condition it responds to, it is still not possible to speak of a disease.

Regarding the definition of illIt must be said that the term is used to name the living being that has been the victim of an illness or disease, regardless of whether or not it is aware of its condition. The role of the patient is also discussed according to the position that each individual assumes when experiencing an illness.