Do you know what the image of a dehydrated person's brain would look like? Thanks to MRI scans we can answer that question.
One study looked at these images after study subjects lost between 2-2.6% of their body weight due to water loss through sweating. They found that brain volume does decrease during dehydration. It makes sense considering what happens to cells when they're deprived of water. They shrink. Similarly, brain volume decreases when dehydrated.
When cells shrink, they also are less efficient at their jobs - growing, dividing, transporting nutrients, producing energy, sending signals to each other, and so on.
Well, the same slow-down effect occurs in the brain's cells. They shrivel. Neurons are made of more than 70% water. When water levels drop, the actual diameter of axons and dendrites decreases making it difficult for brain cells to communicate with each other. The brain now needs to use up more energy to send signals between cells.
This increased consumption of energy leads to symptoms such as mental fatigue, tiredness, lack of concentration, inability to plan, headaches, greater difficulty performing tasks, and moodiness.
How do you reverse the fatigue, the poor mood, the headache, the loss of focus, and the tiredness? Rehydrate to reverse the effects and restore normal brain activity!
Are these effects only seen in severe cases of dehydration? Not at all. Severe cases of dehydration can lead to delirium, coma, and, finally, be fatal. However, the previously mentioned effects appear even during mild or temporary dehydration. This was seen in a 2013 study that saw dehydration effect brain function in as little as 24 hours.
Know the Signs
Although thirst can be used to indicate a need for water, remember other telltale signs of dehydration:
- excessive hunger or cravings may actually indicate you need to hydrate
- lack of focus/foggy concentration
- muscle cramps
- dry mouth
- dark, concentrated urine
- infrequent urination or low urine output
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