Water makes up more than half of our body weight and a person can't survive for more than a few days without it. Why? Your body has lots of important jobs and it needs water to do many of them. For instance, your blood, which contains a lot of water, carries oxygen to all the cells of your body. Without oxygen, those tiny cells would not be able to survive and your body would stop working. In addition to being an important part of the fluids in your body, each cell depends on water to function normally. I did some research and found some of the top reasons to drink more water .