There's a lot of debate on whether or not dehydration causes brain fog. Some people believe that if you're not getting enough fluids, your brain won't be able to function as well. Others say that there's no scientific evidence to support this claim. So, what's the truth?
The short answer is: we don't know for sure. But, there is some evidence that dehydration can lead to cognitive problems. One study showed that students who were dehydrated performed worse on tests of mental agility and memory. Another study found that older adults who were dehydrated were more likely to experience declines in cognitive function.
So, it's plausible that dehydration could cause brain fog. But more research is needed to confirm this link. In the meantime, it's a good idea to drink plenty of water to stay hydrated.