There are upper and lower margin limits for any function of the body. If you go outside of this range, problems occur. The same thing happens with oxygen, oxygen saturation status, a blood glucose concentration, blood pressure. There is that's negative feedback homeostasis? Well, it where it goes, in the opposite of the stimulus,. But at the end of the day, regardless of whether it's positive or negative, it needs to go back within that hely bounte.