Post-surgical pain is a complex response to tissue trauma during surgery that stimulates hypersensitivity of the central nervous system. The result is pain in areas not directly affected by the surgical procedure. Post-operative pain may be experienced by an inpatient or outpatient. It can be felt after any surgical procedure, whether it is minor dental surgery or a triple-bypass heart operation.

Pain is recognized in two different forms: physiologic pain and clinical pain. Physiologic pain comes and goes, and is the result of experiencing a high-intensity sensation. It often acts as a safety mechanism to warn individuals of danger (e.g., a burn, animal scratch, or broken glass). Clinical pain, in contrast, is marked by hypersensitivity to painful stimuli around a localized site, and also is felt in non-injured areas nearby. When a patient undergoes surgery, tissues and nerve endings are traumatized, resulting in incision pain. This trauma overloads the pain receptors that send messages to the spinal cord, which becomes overstimulated. The resultant central sensitization is a type of posttraumatic stress to the spinal cord, which interprets any stimulation—painful or otherwise—as unpleasant. That is why a patient may feel pain in movement or physical touch in locations far from the surgical site.

Patients handle post-operative pain in high individualized ways. Health care professionals have observed that some patients report that they are in extreme pain after surgery, demanding large doses of pain medications while others seem to do well with much less medication. Several theories have been put forth for this discrepancy. For example, differences in body size seemed to require differing amounts of medication, but this theory did not explain differences in pain perception among patients of the same build. Emotional well-being was considered a better indicator of the ability to tolerate pain. It has been theorized that patients with stronger support systems and better attitudes actually perceive less pain than others. Some health care professionals have even speculated that extreme pain was not real in many cases, but was a way to seek attention.

Since pain perception is highly subjective, it is important for the health care team to be aware of pain sensitivity differences in patients, and to value patient self-report as a reliable tool for pain assessment. The most common self-report system in use is the pain intensity scale. The patient is asked to identify where the pain falls on a scale of 0 “no pain at all” to 10 “the worst pain in the world.” This scale, however, does have limitations. The Short-Form McGill Questionnaire, which uses sensory words or synonyms, may allow the patient to communicate more accurate, descriptive information about pain and may be a better tool in planning pain management strategies.

It is clear that there is a real need for providing different approaches to post-surgical pain management. A variety of interventions may be used before, during, and after surgery. Most of these methods involve medications given orally, intravenously, intramuscularly, or topically (via the skin). Some must be administered by a health care professional; others by the patient.