Pain threshold is defined as the minimum intensity of a stimulus that is perceived to be painful. Previously, this threshold was believed to be uniform across individuals, such that given intensity of a stimulus was thought to produce a given pain response. However, it is now understood that the experience of pain is a subjective phenomenon, which is influenced by a complex interaction of biopsychosocial factors.
Historically, Specificity Theory and Pattern Theory posit that pain results from the direct transmission of peripheral stimuli to the brain, and stimulus response occurs in a reproducible relationship. However, limitations to these theories became evident after observing divergent responses to pain across individuals despite objectively similar physical stimuli or trauma. Consequently, Melzack and Wall proposed the Gate Control Theory of pain, which revolutionized our understanding of this phenomenon.
According to this theory, peripheral small diameter nerve fibers...