For the first time in 40 years, a global authority has revised its clinical definition of pain. 

The International Association for the Study of Pain’s new definition emphasizes the effects pain may have on functional abilities as well as on social and psychological well-being. It is also intended to be more inclusive.

To qualify as having “pain” under the old definition, a person needed to be able to describe their experience. This left out people who could not verbally express their pain, including some elderly people and others with communication disorders, according to the IASP task force that re–defined the word. 

The new definition is: “An unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage.”

Among the IASP’s key notes on this change (summarized):

  • Verbal description is only one way pain is expressed; inability to communicate does not rule out the possibility that a person or animal experiences pain.
  • A person’s report of an experience as pain should be respected.
  • Pain is always a personal experience that may be influenced by biological, psychological, and social factors. 

“Pain is not merely a sensation, or limited to signals that travel through the nervous system as a result of tissue damage,” said Srinivasa N. Raja, M.D., with Johns Hopkins University School of Medicine and chair of the IASP task force. “With a better understanding of an individual’s pain experience, we may be able to, through an interdisciplinary approach, add a variety of therapies to personalize their treatment of pain.”

IASP’s original definition of pain has been adopted worldwide as a standard by healthcare providers, pain researchers and several professional, governmental, and nongovernmental organizations, including the World Health Organization.

The reasoning behind the revision was published Thursday in IASP’s journal, Pain.