When you’re dehydrated by just two percent, your cognitive performance drops like a bad Wi-Fi signal. You get foggy, irritable, and suddenly every small task feels like assembling IKEA furniture without instructions.
That’s because your brain is about 80 percent water, and it hates running on fumes. A dry brain is a grumpy brain. And remember: by the time you feel thirsty, you’re already one percent down the drain.
Fun fact: a loss of just 1.5 percent of your body’s water is enough to trigger a headache. So, if your head is throbbing after a long meeting, it might not be your boss’s presentation—it might be you drying out.
What Does Body Water Mean On A Scale at Paul Morrison blog
