When it comes to summer, dehydration and thirst are two common phenomenon that effect people as well as animals. But we don't feel thirsty in winters even though we drink less water. Why does it happen? In fact dehydration is a common problem even in winters and it is worse because we do not have the urge to drink water. It is a universal fact that the human body is about two-thirds water, and when the total water level drops by only a few percent, we can become dehydrated. It has been proven that fluid deficits of 3 to 8 per cent of body mass have been reported in individuals during cold environments and dehydration is a major problem with exercise in the cold.Yet the loss of fluid from our bodies, which triggers thirst in warmer weather, does not draw out the same response when the temperatures dip. It's not simply because we don't feel hot. A study published in the journal Medicine & Science in Sports & Exercise, says that the cold actually alters thirst sensation. During the study, it was found that fluid balance in the body relies on the stimulation of thirst, resulting in voluntary fluid intake, as well as the kidneys conserving or excreting water.According to experts, a great deal of water is lost from our bodies in the winter due to respiratory fluid loss through breathing. And the fluid balance in the human body relies on the stimulation of thirst, resulting in voluntary fluid intake, as well as the kidneys conserving or excreting water. This process is mediated by fluid-regulating hormones such as plasma argentine vasopressin (AVP).Why the body reacts differently during winter?To find out why the body reacts differently in the cold, experts at the University of New Hampshire subjected people to the cold chambers and then they were exposed to exercising on a treadmill and rested. During cold exposure, it was observed that vasoconstriction took place, where the blood flow decreased to the periphery of the body to decrease heat loss.
What experts have also found is, because blood volume at the body's core increases, the brain does not detect blood volume decrease. As a result, AVP hormone is not secreted at the same increased rate, despite elevated blood sodium. Also, kidneys get a diminished signal to conserve fluid, and thirst sensation is reduced by up to 40 per cent.
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Why people feel less thirsty during winter season - Times of India
