The body's initial responses to dehydration are thirst to increase water intake along with decreased urine output to try to conserve water. The urine will become concentrated and more yellow in color.
As the level of water loss increases, more symptoms can become apparent. The following are further signs and symptoms of dehydration:
- dry mouth,
- the eyes stop making tears,
- sweating may stop,
- muscle cramps,
- nausea and vomiting,
- heart palpitations, and
- lightheadedness (especially when standing).
The body tries to maintain cardiac output (the amount of blood that is pumped by the heart to the body); and if the amount of fluid in the intravascular space is decreased, the body tries to compensate for this decrease by increasing the heart rate and making blood vessels constrict to try to maintain blood pressure and blood flow to the vital organs of the body. This coping mechanism begins to fail as the level of dehydration increases.i googled this :o)