Things to know to avoid dehydration
A powerful alarm system in the body makes you feel thirsty and feel the need to drink as soon as your water levels drop
The human body is one of nature’s miracles. In fact, a system is in place to help protect us from dehydration, within certain limits. Here’s what happens…
Why do we get thirsty?
I’m sure that you already know that the feeling of thirst is triggered by not drinking enough water. But to better understand what’s going on inside our bodies, let’s look at our physiology.
We lose approximately 2.5 liters of water every day (through urine, sweat, stools, breathing). In order to maintain a balanced body water content, we need to consume that same quantity of water, through food and beverages.
Since we lose water constantly throughout the day, if we don’t drink enough, our body water content will gradually drop, including in our cardiovascular system. Luckily, we have pressure sensors in our large arteries and in the cardiac cavity, which react very quickly when this happens. They send a message to the brain to secrete a specific hormone (an antidiuretic hormone) that will concentrate the urine (so that the body loses less water, which is why urine gets darker) and trigger the feeling of thirst!
Is everyone this well-equipped?
No, for some people, this alarm system goes off much later than for others. This is the case for elderly people who don’t feel thirsty until they are really dehydrated (the pressure sensors become less sensitive with age). That’s why they get dehydrated so easily.
Those who say that they are rarely thirsty may feel the need to drink but don’t want to listen to their bodies. Or maybe they don’t value the importance of maintaining a good level of hydration all the time. So they are happy drinking a little bit of water, just enough to not feel thirsty.
What are the risks if you don’t drink before you are thirsty ?
If you wait to get thirsty before drinking some water, your urine will be very concentrated (and dark) and your blood pressure may drop slightly. This could cause problems for people with naturally low blood pressures (for instance, 100/50 mmHg instead of 120/60 mmHg). They will often feel tired, and they are more exposed to severe dehydration in hot weather. If urine is chronically dark and concentrated, it increases the risk of bladder stones and urinary tract infections.
An ounce of prevention is worth a pound of cure.