Diseases may be described as organic or functional. The broadest definition is:
- Ann organic disease A condition in which there is a measurable change in a tissue or organ that causes the organ or organ system to malfunction.
- a functional disease A condition in which there are abnormal changes in organ function but no measurable changes in tissues.
The main difference between organic and functional diseases is that the causes and pathophysiology (disease pathways) of organic diseases are largely established, whereas the causes and pathophysiology of functional diseases are largely unknown. is.
Many diseases are classified as either organic or functional. The term may apply not only to physiological conditions (related to the body), but also to mental health conditions.
This article explains the difference between organic and functional disease and why this distinction is important in medical practice.
Distinguishing between organic and functional diseases
The distinction between organic and functional disease is central to disease diagnosis. Its purpose is to distinguish between symptoms and syndromes (groups of symptoms) that can be explained by diagnosable biological changes and those that cannot.
For example, persistent fatigue may be due to organic causes such as anemia, which can ultimately be diagnosed by red blood cell (RBC) counts. Alternatively, it may be due to a functional cause, such as chronic fatigue syndrome, for which there is no measurable test.
This does not mean that the lack of testing means that functional diseases are “less real” than organic diseases. As scientific understanding of a disease improves, the way it is classified may change.
Epilepsy is one example. Seizure disorders, once considered functional, are now considered organic neurological conditions.
Determining whether the cause is organic or functional is important in providing appropriate treatment. It’s not always an easy process.
organic disease
Organic disease refers to a broad category of conditions that affect tissues and organs, causing symptoms and disease. These include infectious diseases, inflammatory diseases, metabolic disorders, neurological diseases, autoimmune diseases, and cancer.
Organic diseases require tests and procedures that can detect or measure biological and/or anatomical changes that lead to disease or dysfunction. These may include blood tests, imaging tests, medical equipment, or surgical procedures.
Examples include:
This does not imply that all organic diseases can be diagnosed in a direct and definitive way. If a single test is not diagnostic, multiple tests may be needed to support the diagnosis.
One example is celiac disease (CD). In addition to antibody tests, small intestine biopsies, and a gluten-free diet, genetic tests called HLA-DQ2 and HLA-DQ8 may be used to see if you have a genetic predisposition to CD. This test does not diagnose CD (you may or may not have these mutations), but it almost certainly rules out CD if the mutations are not present.
Other organic diseases may also require complex tests not only to prove the disease but also to rule out other possible causes, including functional causes.
These include:
functional disease
Broadly speaking, a functional disease is one in which there is no diagnosable pathophysiology that can explain the symptoms. What this means is that an organ or organ system is malfunctioning, but it is unclear exactly where the problem occurs or how it causes symptoms.
Functional diseases can occur when organs do not function properly or when there is some miscommunication between systems (such as the brain and the gut). Symptoms generally persist and cause significant impairment or disability. Symptoms can be confusing but are usually not life-threatening.
Because there are no tests to definitively diagnose functional disorders, diagnosis is usually based on a set of criteria issued by health authorities. Standards may change and evolve as our understanding of the disease increases.
The term “functional disorder” is generally interpreted to mean functional somatoform disorder (meaning physical). This term can also be applied to many, but not all, mental illnesses.
functional somatic disorders
There are many conditions that are classified as functional somatoform disorders (FSDs). These can cause symptoms that are localized to specific organs or can affect the entire body.
Examples include:
It is not uncommon for some of these disorders to overlap. Fibromyalgia and CFS frequently co-occur, suggesting that the two diseases have similar disease origins or pathways.
Functional somatoform disorder should not be confused with somatic symptom disorder (SSD). SSD is a mental condition in which physical symptoms persist due to psychological problems.
Discussing mental illness as a functional condition
Although mental illness meets the strict definition of impairment, there is considerable debate as to whether this term is appropriate in this context.
Mental illness—range of: depression Conditions ranging from bipolar disorder to schizophrenia to post-traumatic distress syndrome (PTSD) remain poorly understood and are diagnosed based on criteria published by the American Psychiatric Association (APA).
However, many mental health professionals argue that labeling them as “functional” suggests that the cause is essentially unknown and the condition “appears out of nowhere.” There is.
Indeed, for conditions such as depression and PTSD, scientists recognize that environmental, social, emotional, and neurological factors contribute to the development of these conditions. Additionally, medications used to treat depression and attention-deficit/hyperactivity disorder (ADHD) have specific neuropsychiatric effects that are more or less consistent than any other medication.
Conditions such as delirium and dementia can be considered “organic” because their characteristics are well-defined, regardless of the underlying disease.
Given the frequent overlap between FSD and SSD, even when it comes to functional impairments, experts question whether they should be strictly categorized as “somatic” and “psychological.” In 2020, European experts agreed that “functional somatoform disorders” should not be classified as either purely physical or purely mental disorders, but as occupying a neutral space between the two. recommended.
summary
Strictly speaking, an organic disease is one in which there are measurable biological changes in tissues or organs that cause symptoms. Examples include infectious diseases, autoimmune diseases, and cancer.
A functional disease is one in which an organ (or the communication between organs) malfunctions, causing symptoms but no measurable changes in tissues. Examples include fibromyalgia, chronic fatigue syndrome, and irritable bowel syndrome.
While the causes and disease pathways of organic diseases are largely established, the causes and disease pathways of functional diseases are poorly understood.
For organic diseases, certain tests, such as blood tests or medical imaging, can confirm the diagnosis. For functional diseases, there are no tests available and diagnosis is primarily based on diagnostic criteria issued by established health authorities.