We've all heard the recommendation to drink eight glasses of water per day. And while the science is still out on exactly how much water you should drink each day, there's no doubt that hydration is essential.
Each day we lose around two to three liters through normal functions like sweating, breathing, and going to the bathroom. But can you drink too much water? Believe it or not, you can!
Known as water intoxication, or water poisoning, it occurs when you drink more water than your body is able to handle. Your blood contains a certain level of sodium that your kidneys regulate. If that level drops too low, say by drinking more water than your kidneys are able to process at once, then your blood becomes diluted and watery, a condition known as hyponatremia. That excess water in your blood is carried around your body where it enters your cells, causing them to swell up like balloons. Now, most of the cells in your body are able to handle putting on a little extra size, but there's one place where you definitely don't want that to happen—the brain. Your brain sits snugly inside the skull, which means it has no room to expand. As your brain swells and the pressure in the skull increases, blood flow is decreased, depriving your brain of oxygen.
以 water intoxication（水中毒），或是 water poisoning 為人所熟知，當你喝下超過你身體負荷量的水，就會發生水中毒。你的血液含有由腎臟調節的特定含量的鈉。如果那個量變得太少，假設因為喝了超過腎臟可以立即處理的水量，那你的血液就會變得稀稀水水的，這是一個被稱為低鈉血的症狀。你血液裡那些過量的水分會被帶到你身體裡的各個地方，進入你的細胞中，使它們像氣球一樣膨脹。你身體裡大部分的細胞都還可以應付多增加幾個尺碼，但有一個你絕對不會想讓這種事發生的地方－－大腦。你的大腦剛剛好塞進你的頭蓋骨裡，那表示它沒有可以膨脹的空間。當你的大腦膨脹，且頭蓋骨裡的壓力上升時，血流下降，讓你的大腦缺氧。
The first symptoms of water poisoning are headaches and nausea. But as the brain swells further, you could have trouble breathing, experience seizures, go into a coma, or even die. The exact amount of water needed to cause water poisoning varies from person to person and depends on a number of factors, like how much you're sweating. But most of the reported cases involve people drinking multiple gallons in just a few hours. So don't force yourself to drink more water than you feel like you need. If you let your thirst be your guide, you should be just fine.
- 「無庸置疑地」- No Doubt
And while the science is still out on exactly how much water you should drink each day, there's no doubt that hydration is essential.
- 「腫脹、膨脹」- Swell Up
That excess water in your blood is carried around your body where it enters your cells, causing them to swell up like balloons.
- 「增加」- Put On
Now, most of the cells in your body are able to handle putting on a little extra size, but there's one place where you definitely don't want that to happen—the brain.