You can live ALL your life......until your are 90 years old with a leaking mitral valve.
You can play tennis, golf and live a normal life ...with a leaking mitral valve.
So what is the rub?
If the left ventricle of your heart starts to complain about the extra work that it is doing in dealing with a "leaky valve" then surgical intervention may be necessary.
How do I know if the left ventricle is complaining?
Because it starts to get bigger.
How do I know if it is getting bigger?
ECG, chest X-Ray, ultrasound and MAYBE.intra oesophageal studies.
Good luck and you to McMouse.