Feeling tired and moody? You could just be in need of a glass of water.
A new video on Ted-Ed, which details the effects of dehydration, reveals your brain actually SHRINKS if starved of water.
While the body is 60 percent water, the brain is actually made up of 75 percent H2O.
A lack of liquid triggers a coping mechanism in your brain which means it reduces in size and has to work harder to carry out normal tasks which can mess with your thinking power.
The effect is to leave you with headaches, mood swings and a lack of energy.
The brain also sends a message to the kidneys to activate aquaporins – channels which allow your body to store more water – which is why your pee gets darker.
Dehydration also effects the skin, meaning dryness and itchy patches.
Water also helps lubricate joints, protect the spine and regulate body temperature.
Staying hydrated also lowers chances of stroke and diabetes and may even help lower the chance of cancer.
Doctors advise that men need to drink between 2.5 to 3.7 litres a day while women need two to 2.7 litres.
So get guzzling.