2. You could have more frequent urination
For years, people and even experts have named coffee as a diuretic, trying to explain why many frequent coffee drinkers urinate often. Continued studies have not linked the ingredients in coffee as contributing to frequent urination, rather the fact that when you drink more, you urinate more.
So, if you drink a lot of coffee, expect a lot of that liquid to go where other liquids go: to your bladder to be emptied out when full.