Hey Kirsten,
Our kidneys can process water 200L a day, and only 1.5 - 2 L that goes to the bladder as urine. At least we need 2 L of water a day to help our body function very well. And water also can be excreted as faeces, sweating, when we breathe out, water is important in water and sodium metabolism in the body. If you sweat or work out a lot, that shouldn't be the case, although we expire water vapour when we breathe out, but for average person that have sedentary life or low physical exercise, excessive drinking too much will not help you also, it is enough to drink recommended 2L water a day. When you drink too much water it may cause imbalance in water and sodium of your body, which may cause other consequences, further enquiries you should ask more to your doctor.