Cause of illness

Cause of illness (Greek: 'aitiā' - cause; 'logos' - science) otherwise also etiopathogenesis or etiology.

Etiopathogenesis is a description of the origin of a disease, including both its cause and etiology and other processes that accompany its origin and development.

We refer to the factor that causes the disease as an "etiological factor" - noxa or etiological agent.

We distinguish the causes:
 * internal – endogenous,


 * external – exogenous,


 * or combined.

Exogenous causes
Exogenous causes of disease can be physical, chemical or biological.

Physical causes
The physical causes of the disease include, for example, mechanical effects, the effect of temperature changes, ionizing radiation and electric current, or sudden changes in atmospheric pressure.


 * Mechanical influences - cause injuries or pressure sores.


 * Temperature Changes - cause burns or conversely Frostbites. Hypothermia or overheating occurs due to the overall effect of abnormal temperature on the organism.


 * Ionizing radiation - causes for example Radiation sickness.


 * Atmospheric Pressure Changes - causes caisson sickness or altitude sickness.

Chemical influences

 * Chemicals - such as lyes, acids or poisons (e.g. snakes).


 * Toxic effect of drugs on the body - causes, for example, hepatotoxicity, nephrotoxicity, neurotoxicity.

Biological influences
This group includes all viruses, bacteria or parasites.

Endogenous causes
The endogenous cause of the disease can arise from the genetic information of the individual, when various mutations are applied - for example cystic fibrosis or hemophilia.

They can also represent susceptibility to disease - predisposition, such as age, gender or family burden.

Other types of distribution
Furthermore, the causes of the disease can be divided into somatogenic, psychogenic and others.


 * 'Somatogenic (somatic) diseases have a certain organic basis, such as inflammation, tumor or vascular changes.
 * Psychogenic (psychosomatic) diseases are those for which we cannot find an organic basis. The mutual influence of the mental and physical state is well known, and the significant effect of the psyche has also been shown in a number of diseases. This relationship is noticeable, for example, in bronchial asthma, stomach ulcer, eczema and inflammatory bowel diseases. Asthma attacks provoked by mental stress are known, for example. Therefore, psychotherapy is mainly used in treatment.


 * Iatrogenic (Greek: iatros – doctor) diseases are diseases caused by a doctor.

If the cause is unknown, we refer to the condition as 'idiopathic (essential, cryptogenic).


 * 'Monofactorial disease arises on the basis of one etiological factor.
 * A 'multifactorial disease is one whose occurrence requires the simultaneous action of several main etiological factors. For example, the family burden factor and the exogenous factor – early ischemic heart disease in the family history and smoking.


 * Congenital diseases are caused by factors that act prenatally, such as various teratogens.


 * Etiological factors acting postnatally cause acquired diseases (lat. acquīrere - to get).

It is therefore important in which period the etiological factor was active, not when the disease began to manifest itself clinically.

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