FEVER AND IT'S EFFECTS ON THE HUMAN BODY

OBJECTIVES OF THE DISCUSSION: By the end of this discussion, the reader/medical student will be able to;

1.  Describe the term fever/pyrexia

2.  Identify the different causes of fever

3.  Outline the means by which fever can be prevented

INTRODUCTION: A fever is an abnormally high body temperature and may accompany infectious diseases, extensive physical trauma, cancer, or damage to the Central Nervous System. The substances that may cause a fever are called pyrogens. Pyrogens include bacteria, foreign proteins, and chemicals released during inflammation. Bacteria: Proteins: Inflammation  

These inflammatory chemicals are called endogenous pyrogens. It is believed that pyrogens chemically affect the hypothalamus and raise the setting of the hypothalamic thermostat. The hypothalamus will then stimulate responses by the body to raise body temperature to this higher setting.

PURPOSE OF FEVER: White blood cells increase their activity at moderately elevated temperatures, and the metabolism of some pathogens is inhibited. Thus, a fever may be beneficial in that it may shorten the duration of an infection by accelerating the destruction of the pathogen.

CONSEQUENCES OF HIGH FEVERS: High fevers, may have serious consequences. A fever increases the metabolic rate, which increases heat production, which in turn raises body temperature even more. This is a positive feedback mechanism that will continue until an external event such as, administration of an NSAID or death of the pathogens acts as a brake.

When the body temperature rises above 41°C, the hypothalamus begins to lose its ability to regulate temperature. The proteins of cells, especially the enzymes, are also damaged by such high temperatures. Enzymes become denatured, that is, lose their shape and do not catalyze the reactions necessary within cells. As a result, cells begin to die. This is most serious in the brain, because neurons cannot be replaced, and cellular death is the cause of brain damage that may follow a prolonged high fever.

CONTROL OF FEVERS: To help lower a high fever, the body may be cooled by sponging it with cool water. The excessive body heat will cause this external water to evaporate, thus reducing temperature. A very high fever requires medical attention.

RELATED;

1.  THE INFLAMMATORY PROCESS

2.  INFLAMMATORY CONDITIONS AND THE HUMAN BODY

3.  ANTIPYRETICS

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