Drinking from 3 to 4 cups of coffee per day is a healthy amount and if you drink more than 4 cups of coffee per day then it could be bad for your health and kidneys.
Drinking too much coffee can also keep some people awake at night especially when they drink the coffee an hour or so before bed.
Drinking between 3 to 4 cups of coffee per day could also have health benefits such as improving your heart health and preventing heart disease.
Some people do drink more than 4 cups of coffee per day and are perfectly fine but if you start noticing some problems then you should cut down on your coffee intake.