Hyperventilation reduces sensitivity to environmental threats.
Hyperventilation is a common response to unexpected stressors in daily life, such as acute pain or fear. Researchers from the University of Tsukuba and Niigata University of Health and Welfare have revealed that a change in blood gas caused by intense breathing, known as hyperventilation, can desensitize the body to temperature changes. This could reduce our ability to respond to environmental threats.
To explore this, the researchers tested the sensitivity to temperature changes in young adults while breathing normally. They then asked them to breathe rapidly (hyperventilate), with or without the addition of carbon dioxide to their inspired air. The results showed that local detection of warm and cool stimuli was blunted when subjects hyperventilated with hypocapnia, but did not differ when they hyperventilated with normocapnia.
The researchers also observed less blood flow to the brain during hyperventilation with hypocapnia than during hyperventilation with normocapnia. This suggests that hypocapnia may be a mechanism by which hyperventilation reduces sensitivity to stress, while paradoxically dampening thermoregulatory behavior in severe hot and cold environments, which may contribute to heat stroke and accidental hypothermia.
The findings from this study suggest that hyperventilation-induced hypocapnia can reduce our ability to respond to environmental threats. It can also desensitize the body to temperature changes, which may contribute to heat stroke and accidental hypothermia. It is important to note that hyperventilation per se does not reduce sensitivity to temperature changes, but hypocapnia does. Therefore, it is important to be aware of this response and take steps to avoid it.
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