Anorexia (symptom)

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Anorexia
ICD-10 R63.0
ICD-9 783.0
MeSH D000855

Anorexia is the decreased sensation of appetite. While the term in non-scientific publications is often used interchangeably with anorexia nervosa, many possible causes exist for a decreased appetite, some of which may be harmless, while others indicate a serious clinical condition or pose a significant risk.

For example, anorexia of infection is part of the acute phase response (APR) to infection. The APR can be triggered by lipopolysaccharides and peptidoglycans from bacterial cell walls, bacterial DNA, double-stranded viral RNA, and viral glycoproteins, which can trigger production of a variety of proinflammatory cytokines. These can have an indirect effect on appetite by a number of means, including peripheral afferents from their sites of production in the body, by enhancing production of leptin from fat stores. Inflammatory cytokines can also signal to the central nervous system more directly by specialized transport mechanisms through the blood–brain barrier, via circumventricular organs (which are outside the barrier), or by triggering production of eicosanoids in the endothelial cells of the brain vasculature. Ultimately the control of appetite by this mechanism is thought to be mediated by the same factors normally controlling appetite, such as neurotransmitters (serotonin, dopamine, histamine, norepinephrine, corticotropin releasing factor, neuropeptide Y, and α-melanocyte-stimulating hormone).[1]

Causes[edit]

Clinically important causes[edit]

Drugs[edit]

Other[edit]

  • During the post-operative recovery period for a tonsillectomy or adenoidectomy, it is common for adult patients to experience a lack of appetite until their throat significantly heals (usually between 10–14 days).[4]
  • Altitude sickness
  • Significant emotional pain caused by an event (rather than a mental disorder) can cause an individual to temporarily lose all interest in food
  • Physical exercise

References[edit]

  1. ^ Langhans W (October 2000). "Anorexia of infection: current prospects". Nutrition 16 (10): 996–1005. doi:10.1016/s0899-9007(00)00421-4. PMID 11054606. 
  2. ^ Exton, M. S. (1997). "Infection-Induced Anorexia: Active Host Defence Strategy". Appetite 29 (3): 369–383. doi:10.1006/appe.1997.0116. PMID 9468766.  edit
  3. ^ Murray, M. J.; Murray, A. B. (1979). "Anorexia of infection as a mechanism of host defense". The American journal of clinical nutrition 32 (3): 593–596. PMID 283688.  edit
  4. ^ Home Care After Tonsillectomy and Adenoidectomy