First case was in highschool, minor overuse in my right wrist from practicing too much
Severe overuse wrist injury my second year at college, (if you are a cello player/teacher DO NOT TEACH BASSISTS!!!!) took several years to heal and I don't think it ever came back 100%.
Tore a few muscles in my wrist and jacked up the tendons during a local kyokushin tournament. Took almost a year to heal.
Result: Can't play anything anymore for more than 20 minutes at a time without pain. (Which is longer than it used to be just a couple of years ago)
Pay attention to your nutrition and make sure you're getting everything you need or healing will never happen for you. In my case I've had to invest in several Powerwebs and I think they have helped me regain the use of my butchered wrists. Tendons take alot longer to heal than bone.
Where do you work? I used to do physical labor in warehouses and grocery stores and I honestly wish I never did it. Overuse injuries were common enough just from that crap, then I would go home and practice.