How Dehydration Affects Your Brain

Your body contains about 11 gallons of water: Your blood is 85 percent water; your muscles 80 percent; your brain 75 percent and your bones are 25 percent water, which illustrates the importance water plays in your health
Drinking 16 ounces of water can raise your metabolic rate by as much as 30 percent; a 2 percent level of dehydration has been shown to cause a 10 percent decrease in athletic performance
When dehydrated, your brain shrinks in volume. This shrinking is what causes a dehydration headache. Even mild or temporary dehydration can alter your brain function and impact your mood
Dehydration-induced effects such as sleepiness, fatigue, moodiness and confusion are easily reversed within 20 minutes of drinking some water. Cold water absorbs 20 percent faster than tepid water, so to increase the speed of recuperation, drink chilled water.