[troutman]

The Water Myth
It is a common belief that you have to drink 6-8 glasses of water per day, but this myth comes from a fundamental misunderstanding of some basic physiology.

https://www.mcgill.ca/oss/article/he...ion/water-myth

It is a common belief that you have to drink 6-8 glasses of water per day. Almost everyone has heard this recommendation at some point although if you were to ask someone why you need to drink this much water every day, they probably wouldn’t be able to tell you. There is usually some vague idea that you need to drink water to flush toxins out of your system. Perhaps someone will suggest that drinking water is good for your kidneys since they filter the blood and regulate water balance. Unfortunately, none of these ideas is quite true and the 6-8 glasses myth comes from a fundamental misunderstanding of some basic physiology.

If you are thirsty, drink water. If you are not thirsty, then you do not need to go out and purposefully drink 6-8 glasses of water a day since you will probably get all the water in your regular diet. One important caveat to remember though is that on hot summer days, your water losses from sweating go up and if you plan to spend some time out doors, having water with you is important to avoid dehydration and heat stroke. While the thirst reflex is pretty reliable, it does tend to fade with age and older people are more likely to become dehydrated without realizing it. Thus, the take home message is drink water when you are thirsty, but on very hot days it might not be a bad idea to stay ahead of the curve and keep hydrated.

There is a common notion out there that water, given that it is so critical for life, must be able to prevent disease. Sadly, drinking more than the necessary daily amount will not flush toxins out of your system, nor will it help your kidneys. The only change you will see is that your urine goes from yellow to clear, which actually has no medical implications for your health. So, you don’t have to waste any energy worrying about getting your 6-8 glasses of water a day. You have been unconsciously been doing it every day of your life.

https://www.uab.edu/news/youcanuse/i...-of-water-myth

Overhydration
“When people drink too much water, it dilutes the sodium in the blood to a level that is too low.”

Some of the symptoms of low blood sodium, or hyponatremia, are the same as dehydration — nausea, vomiting, headaches, convulsions, brain swelling — and can even cause death.

https://www.mdlinx.com/article/8-gla...icine/lfc-2814