The effect of pain on human sweating

Area of Science:

• Physiology
• Psychophysiology

Background:

• Emotional sweating is a complex physiological response.
• The relationship between pain perception and sudomotor activity is not fully understood.

Purpose of the Study:

• To investigate the effects of various painful stimuli on emotional sweating.
• To compare the sudomotor response to pain versus mental stress.

Main Methods:

• Subjects were exposed to painful stimuli including pinpricks, cold immersion, chest compression, and ischemic exercise.
• Sweating rate was continuously monitored by measuring total body weight loss.
• Mental arithmetic tasks were used as a non-painful stressor.

Main Results:

• Ischemic forearm exercise was the only painful stimulus that significantly increased sweat secretion.
• Mental arithmetic tasks induced a greater increase in sweating compared to most pain stimuli.
• Severe pain, under laboratory conditions, did not consistently elicit significant sweating.

Conclusions:

• Many types of pain, even when severe, are ineffective in inducing sweating.
• Psychological stressors, such as mental arithmetic, are more potent in eliciting emotional sweating than physical pain stimuli.