 Water is a compound with a chemical symbol H2O, it's made of hydrogen and oxygen, and without it, life as we know it would not exist on earth. But what about humans? How much of your body do you think is made of water? Our bodies are made of about 70% water. Some tissues and organs are more watery than others. I'm sure you've heard about the importance of drinking enough water and what happens to your body if you get dehydrated. But can you have too much of a good thing? In this video we will discuss what happens if you don't have enough water in your body and also what happens if you drink too much. This is called the water balance. Organs in your body work together to maintain this water balance in homeostasis. Every organism needs water to survive, though some need more water than others. Why do you think your body needs water? Pause the video here and have a think. All of your body cells need water, as you need it to help regulate your temperature and maintain other bodily functions, such as carrying substances around the body and the blood, and removing waste substances in urine. It's also needed in many chemical reactions. But how does your body lose water? Water is lost through breathing, sweating and digestion. It's important to rehydrate by drinking fluids and eating foods that contain water in order to maintain the water balance. If you do not digest enough, you can become dehydrated. Pause the video here and try to think of some symptoms of dehydration. Symptoms of dehydration include feeling thirsty, dark yellow and strong smelling urine, feeling dizzy or lightheaded, feeling tired and dry mouth, lips and eyes. If a person goes three days without drinking water, they will probably die. This can be compared to food where someone can survive weeks without eating. The water balance inside the body is maintained by the kidneys. If we drink too much water, the kidneys produce more urine. If we drink too little, the kidneys produce less urine. However, the kidneys can only remove a certain amount at a time. If not enough water is removed by the kidneys, the amount of water in the body cells increase, causing the cells to swell. If the cells absorb too much water, they can burst. This happens to animal cells, because they do not have a cell wall, remember? Plant cells simply become turgid. Most parts of your body will allow their cells to expand a bit, but there is no room inside the skull for the brain cells to expand. Swelling of the brain can cause confusion, headaches, seizures, comas and even death. But this is extremely unlikely to occur when just drinking too much normally. There is, however, something that can cause this to happen more easily. Users of the drug MDMA are more likely to suffer from hyperhydration. MDMA has many different names, one of which you probably heard before, ecstasy. The drug gives users a sense of euphoria. It also reduces urine production, while simultaneously making users feel thirsty. This means they add more fluid to their bodies, while at the same time removing less. This leads to an overall increase in the water levels in the body and swelling of the brain. This is one reason why the use of MDMA or ecstasy is so dangerous. So now you can see how water is necessary for so many processes in our bodies, but too much of it is dangerous. As with most things in life, it's all about finding the right balance. If you liked the video, give it a thumbs up and don't forget to subscribe, comment below if you have any questions. Why not check out our Fuse School app as well? Until next time.