How do i know if sepsis case is mild?

Mild ? By its nature sepsis is considered serious. People can have bacteria in the bloodstream (bacteremia) and it may clear naturally in rare cases or be successfully treated if quickly noted. The term sepsis implies that the bodies normal functions like blood pressure, cognition, circulation are affected by the illness and the person is lucky to survive.

It is not a do it yourself issue and if you have fever it would be prudent to see a doctor.

There is truly no such thing as a "mild" case of full-blown septicemia. Sepsis is a life-threatening medical crisis and needs thorough inpatient hospital care.