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12.2. The disease and types of diseases

The disease and types of diseases

When something in our body does not work properly, disease occurs, which can be classified:

  • According to its duration:
    • Acute: illnesses that last a short time, generally less than three months.
    • Subacute: diseases that last between three and six months .
    • Chronic: diseases that last more than six months, continuing over time.
  • According to its distribution. Depending on the number of people affected and the geographic area over which it spreads, the disease can be:
    • Sporadic: affects very few people, and appears occasionally.
    • Endemic: it affects people from the same population or geographical area and is maintained over time.
    • Epidemic: affects a large number of people in a certain area.
    • Pandemic: it is an epidemic that affects large geographic areas (up to global distribution), generally during a specific time .
  • According to the type of alteration:
    • Traumatic diseases: They are those caused by blows or traffic accidents, domestic, sports, work, etc. For example, broken bones.
    • Environmental diseases: They are caused by environmental agents, such as cold, heat, radiation, etc. For example, burns.
    • Toxic diseases: They are produced by ingesting or inhaling products that are harmful to the body. For example, inhalation of chemicals.
    • Metabolic diseases: Caused by an alteration of metabolism. For example, diabetes.
    • Degenerative diseases: They consist of the anatomical and functional alteration of the tissues of any organ, apparatus or system. For example, osteoarthritis.
    • Neoplastic diseases: Produced by the division of cells in a tissue. For example, leukemia.
    • Mental illnesses: They affect the psychic behavior of the individual and can be caused by organic brain lesions, psychosis and dementias, or have no known cause, such as phobias.
  • According to its origin:
    • Infectious diseases: Diseases caused by pathogenic microorganisms  (such as bacteria, fungi, viruses, and sometimes protozoa, etc.) or by prions that penetrate our body and reproduce, causing an infection. If the pathogens are macroscopic, such as worms, instead of talking about infection it is called an infestation.
    • Non-infectious diseases: They are those that are not produced by pathogenic microorganisms, so they are not contagious.


Answer in your notebook

12.3.- Name any disease that has produced a pandemic or pandemic risk in recent years.