One of the most important ways of looking after your body is keeping hydrated. Here are some signs of dehydration you should look out for. Bad breath has many causes, but dehydration is one of them - your saliva production goes down making it less likely to kill odors from food. You feel hungry all the time. Next time you’re feeling peckish for a snack, it may just be your body telling you it needs water. Headaches are a notorious symptom of dehydration. Being dehydrated can cause fluid to shift out of the brain, resulting in a pounding pain. Dehydration can also lead to trouble performing visual tasks. So, not being able to focus may be your body needing fluids. Constipation is another key sign of dehydration. Water regulates and aids digestion so that food can pass through your system healthily. Dehydration can cause neurological effects that lead to irritability. So, next time you're in a bad mood, drinking some water might cheer you up!