how do you know when your body needs water
2 You May Need More Water If You're Thirsty. Thirst is the desire to drink something. It can be triggered by the loss of fluid volume in and around cells and in the blood. Thirst is your body's way of saying you need water to avoid dehydration.
1 If you are constipated (can't do a poo when you feel like you should be able to), drinking more water may help. Have a look at our topic 'Constipation - when you just can't go'.  If you are sick then sip water often to keep up the fluid levels in your body.
1 Using muscles a lot makes lot of heat in your body. If you are getting all red in the face and sweaty then you need to slow down, cool down and drink extra water.  If you are constipated (can't do a poo when you feel like you should be able to), drinking more water may help.