It’s possible you already know water is the human body’s major single component this is the same for the human brain and critical for life. Various factors usually determine the length of time a human being can survive without water. In extreme conditions, you should expect death to be rapid, such as a runner exercising hard in the hottest weather.
In such conditions, the individual can dehydrate and as the body overheats he or she could die in a couple of hours without proper hydration. On the other hand, an adult who is in a comfortable environment is able to survive for 7 days or more without water or with a limited intake of the precious liquid.
Water balance critical
For humans to remain healthy, water balance needs to be maintained, meaning that water intake has to make up for a loss of the liquid. We acquire water from drinking it directly and in food before losing it in the form of urine and sweat with faeces also containing a little amount. Water loss also takes place during exhalation since the air exhaled is usually saturated with water. This can be observed on a very cold day where the condensation of the water within the air takes place.
High temperature and extreme conditions
If people are exposed to hot surroundings or engage in vigorous exercises, the result is an increase in temperature within the body. Sweating is the only human physiological mechanism that keeps them from overheating. As sweat evaporates, blood within vessels is cooled within the skin cooling the whole body. An adult exposed to extreme conditions produces about a litre and a half of sweat every 60 seconds.
Water must be replaced
In case lost water is not replaced, it’s possible for the entire body fluid volume to reduce rapidly, which can also be very dangerous if in the process the volume of blood also drops. Once this has happened the result will be soaring body temperature, zero sweating and decrease of blood pressure due to low volume of blood. In such circumstances, the person can die rapidly. Since children have a bigger skin surface in contrast with volume ratio, they are highly susceptible to quick dehydration and overheating.
Overheating and dehydration
Every year, overheating and dehydration send thousands of people to A& E departments. Also, kidney failure, excessive vomiting and diarrhoea are also a serious cause of dehydration. Humans can remain hydrated through an intake of diverse fluids as well as water, although there are exceptions; intake of alcohol brings about dehydration as ethanol slows down the level of AVP (arginine vasopressin), an anti-diuretic hormone. This raises the volume of urine to a point where there is a loss of water than water taken in with the alcoholic beverage.