|
When we feel thirsty and have nothing to drink, we may suffer so much that we can think of nothing else. All of us have the experience of being thirsty at times—but can you imagine how it would feel to be thirsty for days and days? If a human being has absolutely nothing to drink for three weeks, he will die.
Our body simply needs to replenish its liquid supply—and yet between 50 and 60 per cent of our weight is water! As a matter of fact, in the course of a day the average adult loses about two-thirds of a liter of water through perspiration, and excretes about a liter of water to get rid of waste products.
On the other hand, whether we drink or not, we also take in water. When the body digests food, it obtains almost a third of a liter of liquid from this food per day. But this process of losing water and gaining it isn’t enough to keep the balance of water our body needs. Thirst is the signal our body gives us that it needs more water.
Dryness in the mouth or throat is not what causes thirst, as many people believe. |
|
|
That dryness may be caused by many things such as nervousness, exercise, or just a slowing-up of the flow of saliva. It is possible to make the saliva flow again (for example, with a little lemon juice), but this will not take care of our thirst.
In fact, your saliva can be flowing freely, your stomach and blood stream and bladder may be full of water—and you can still be thirsty! For example, people who drink whiskey at a bar may have taken several drinks and still feel thirsty—if they happen to have munched on salty peanuts or pretzels between drinks!
The reason for this is that thirst is caused by a change in the salt content of our blood. There is a certain normal amount of salt and water in our blood. When this changes by having more salt in relation to water in our blood, thirst results.
In our brain, there is a “thirst center.” It responds to the amount of salt in our blood. When there is a change, it sends messages to the back of the throat. From there, messages go back to the brain, and it is this combination of feelings that makes us say we’re thirsty.
|
|
