The soundpost is the dowel made of spruce that transfers the vibrations from the top of the instrument to the back.
A correctly maintained bridge can last for many years.
You may notice that your instrument's pegs may slip from time to time, which is not necessarily an indication that the pegs do not fit.
Any wood will shrink in low humidity and expand in high humidity. This shrinking and expanding process can have severe consequences for an instrument.
It is helpful to have a humidifier in the room where you practice.