In medicine, a disorder is a functional abnormality or disturbance.[1][2]
In many cases, the terms "disorder", "disease" and "illness" are used interchangeably.[3] However, the term "disorder" is often considered more value-neutral than the term "disease", and is preferred by some patients with these conditions.[citation needed]
Medical disorders can be categorized into mental disorders or physical disorders. Mental disorder is the far more common term and physical disorder is mostly used just for distinction purposes.