Nociception

Pain is a distressing sensation often caused by intense or damaging stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage."

acute pain extending beyond the usual healing process

A nociceptor () is a sensory neuron that responds to damaging or potentially damaging stimuli by sending "possible threat" signals to the spinal cord and the brain. The brain creates the sensation of pain to direct attention to the body part, so the threat can be mitigated; this process is called nociception.

In physiology, nociception , also nocioception (), is the sensory nervous system's process of encoding noxious stimuli. It deals with a series of events and processes required for an organism to receive a painful stimulus, convert it to a molecular signal, and recognize and characterize the signal to trigger an appropriate defensive response.

pain in the pelvic region

guideline for the use of drugs in the management of pain

Medication used for other purposes that additionally has analgesic effects

distress in human infants as a response to damaging stimuli

Enkephalinases are enzymes that degrade endogenous enkephalin opioid peptides. They include: Aminopeptidase N (APN) Neutral endopeptidase (NEP) Dipeptidyl peptidase 3 (DPP3) Carboxypeptidase A6 (CPA6) Leucyl/cystinyl aminopeptidase (LNPEP) Angiotensin-converting enzyme (ACE)