I Have Been Diagnosed With A Synovial Cyst In My

I have been diagnosed with a synovial cyst in my spinal facet joint at the L4-L5 area via MRI. I also have two cysts on my hands. These are all fluid filled and cam on at the same time. What could cause this sudden onset of cysts? I am only 26 years old and very healthy, active, etc. I have never had any health ailments aside from injuries related to sports.