What Is an Organic Disease?

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Organic disease is the term used to describe any health condition in which there is an observable and measurable disease process, such as inflammation or tissue damage. An organic disease is one that can be validated and quantified through the use of biomarkers - biological measures of disease. With an organic disease there are physiological changes within the tissues or organs of the body. These changes are detectable, observable, anatomical and/or structural.

Types of Organic Diseases

Organic diseases can be localized, meaning they affect only a concentrated area of the body, or they can be systemic, meaning that they affect many systems throughout the body. They can be hereditary or arise from internal or environmental factors. Some diseases are communicable, meaning that they can be passed on to others, while other organic diseases are non-communicable.

Some of the broader categories of organic disease include:

  • Autoimmune disease
  • Cancer (bone, organ, blood)
  • Inflammatory conditions affecting various organs or tissue
  • Infectious diseases (bacterial, viral, blood-borne)

Some examples of organic disease include:

Organic Disease Versus Functional Symptoms and Disorders

The term organic disease is often used in contrast to disorders that are seen as functional. Functional disorders are those in which no disease process is visible through standard diagnostic testing.

In the past, such functional disorders were seen as psychological in origin, but it is now recognized that this is not a full or true picture of these complex health conditions.

Functional symptoms are symptoms that a patient experiences for which no clear-cut organic disease can be identified as causing the symptom.

Some examples of symptoms that may be considered functional if no disease process can be identified include:

  • Abdominal pain
  • Back pain
  • Fatigue
  • Headaches
  • Indigestion
  • Insomnia
  • Irritability

Functional Gastrointestinal Disorders

Irritable bowel syndrome (IBS), is a prime example of a functional health problem. Its diagnosis requires that any organic disease be ruled out, such as celiac disease or colon cancer. As such, IBS is classified as a functional gastrointestinal disorder (FGD). Other examples of FGDs include:

Non GI-Related Organic Versus Functional Disorders

It is not just in the area of digestive symptoms that doctors need to make a distinction between organic disease and functional disorders. Two common examples are making a distinction between rheumatoid arthritis and fibromyalgia or chronic recurrent urinary tract infections versus interstitial cystitis.


Drossman, D. "The Functional Gastrointestinal Disorders and the Rome III Process" Gastroenterology 2006 130:1377-1390.

"Rome III Diagnostic Criteria For Functional Gastrointestinal Disorders"

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