The embodiments herein relate to a method performed by an analyzing device for handling dynamic characteristics of a vibrating machine component. The analyzing device monitors vibration of the machine component in real-time. When the vibration of the machine component is below and close to a threshold, the analyzing device provides a real-time indication of that the vibration of the machine component is below and close to the threshold. The analyzing device obtains the dynamic characteristics of the machine component when the vibration is below and close to the threshold. A change of the dynamic characteristics influences how close the vibration is to the threshold.