Nature may call in different forms, be it when you feel thirsty, or when you are sleepy, or when you are hungry, or when you need to use restroom. Don’t hold yourself back when you hear nature’s call.
That is, drink when you are thirty, eat when you are hungry. Go to bed when you are sleepy, slow down when you are tired. And of course, go to restroom when you need to. It will be detrimental to your health if you keep doing what you are doing and ignore nature’s call.