Functional symptom

A functional symptom is a medical symptom in an individual which is very broadly conceived as arising from a problem in nervous system 'functioning' and not due to a structural or pathologically defined disease cause. Functional symptoms are increasingly viewed within a framework in which psychological, physiological and biological factors should be considered to be relevant.

Historically, there has often been fierce debate about whether certain problems are predominantly related to an abnormality of structure (disease) or function (abnormal nervous system functioning), and what are at one stage posited to be functional symptoms are sometimes later reclassified as organic as investigative techniques improve. An example is functional constipation, which may have psychological or psychiatric causes. However, one type of apparently functional constipation, anismus, may have a neurological (physical) basis.

Whilst misdiagnosis of functional symptoms does occur, in neurology, for example, this appears to occur no more frequently than of other neurological or psychiatric syndromes.

However, more commonly the trend is to see functional symptoms and syndromes such as fibromyalgia, irritable bowel syndrome and functional neurological symptoms such as functional weakness as symptoms in which both biological and psychological factors are relevant, without one necessarily being dominant.

External links

• Functional somatic symptoms and syndromes
• Engagement in psychological treatment for functional neurological symptoms--Barriers and solutions
• Chronic multiple functional somatic symptoms
• Functional symptoms in inflammatory bowel disease and their potential influence in misclassification of clinical status