Pain tolerance

Pain tolerance is the amount of pain that a person can withstand before breaking down emotionally and/or physically. Pain tolerance is distinct from a pain threshold (the minimum stimulus necessary to produce pain). A dolorimeter is an instrument used to measure pain tolerance.

Exposure to pain as tolerance booster
It is widely believed that regular exposure to painful stimuli will increase pain tolerance - i.e. increase the ability of the individual to handle pain by becoming more conditioned to it. However, this is not true - the greater exposure to pain will result in more painful future exposures. Repeated exposure bombards pain synapses with repetitive input, increasing their responsiveness to later stimuli, through a process similar to learning. Therefore, although the individual may learn cognitive methods of coping with pain, these methods may not be sufficient to cope with the boosted response to future painful stimuli. "An intense barrage of painful stimuli potentiates the cells responsive to pain so that they respond more vigorously to minor stimulation in the future."

Because of this, trauma victims (or patients in pain) are given pain-killers (such as morphine) as soon as possible - to prevent pain sensitization.

Kalat suggest that morphine should be taken before surgery ; "People who begin taking morphine before surgery need less of it afterward. "

Factors affecting pain tolerance
Clinical studies by the journal of Psychosomatic Medicine found that "men had higher pain thresholds and tolerances and lower pain ratings than women". The study asked participants to submerge their hands in ice water (the cold pressor pain procedure) and were compensated financially for keeping their hand submerged. A similar study by the same journal focused on the effects of having individuals perform the ice water procedure while accompanied by another participant. Their results revealed that "Participants in the active support and passive support conditions reported less pain than participants in the alone and interaction conditions, regardless of whether they were paired with a friend or stranger. These data suggest that the presence of an individual who provides passive or active support reduces experimental pain."