A disease can sometimes be described as being organic or functional.
Many diseases fall under the umbrella of being either organic or functional.
This article explains the difference between organic and functional diseases and why the distinction is important in medical practice.
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Or, it could be due to a functional cause likechronic fatigue syndromefor which no measurable test is available.
As the scientific understanding of a disease advances, the way in which that disease is categorized can change.
Epilepsyis one such example.
While the seizure disorder was once considered functional, it is now regarded as an organic neurological condition.
Determining whether the cause is organic or functional is central to delivering the appropriate treatment.
It is not always a straightforward process.
These include infectious diseases, inflammatory diseases, metabolic disorders, neurological diseases, autoimmune disorders, and cancer.
These may involve blood tests, imaging studies, medical instruments, or surgical procedures.
Some require multiple tests to support the diagnosis when a single test is unable to do so.
One example isceliac disease (CD).
The symptoms are generally persistent and cause significant impairment or disability.
While the symptoms may be disruptive, they are generally not life-threatening.
The criteria can change and evolve as the understanding of the disease expands.
The term can also be applied to many, but not all, psychiatric illnesses.
Functional Somatic Disorders
There are many conditions classified as functional somatic disorders (FSDs).
These can cause symptoms limited to certain organs or affect the body as a whole.
Functional somatic disorders should not be confused withsomatic symptom disorder (SSD).
SSD is a condition in which persistent physical symptoms are due to psychological problems.
Examples of conditions classified as FSDs include:
It is not uncommon for some of these disorders to overlap.
Fibromyalgia and ME/CFS frequently co-occur, suggesting that the two disorders have similar disease origins or pathways.
Examples include infections, autoimmune diseases, and cancer.
A functional disease is one in which there are symptoms but with no measurable changes in tissues.
Examples include fibromyalgia, chronic fatigue syndrome, and irritable bowel syndrome.
With an organic disease, the diagnosis can be confirmed with specific tests like blood tests and medical imaging.
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