Writing about the same subject, Stu Littlefair recommended “
if you want to avoid mistakes, talk to a man who's made them all”. I’m your man.
At some point you're almost certainly going to get injured if you're trying remotely hard. So congratulations!
It's common for there to be no definitive identifiable reason why it happens but, on reflection, there are sometimes clues. These vary from person to person so, to some degree, you have to become an 'expert patient'.
There is considerable evidence that anxiety and low mood predisposes to pain and injury. The mechanism is unclear but involves many factors perhaps including elevated cortisol. Cortisol tests might represent Pete's dashboard light in the future if a strong link is demonstrated. In the meantime, look after yourself. People living in shitty environments or who have greater life stresses, like migrants, are more prone to aches and pains above and beyond other covariants like poverty and socioeconomic status. Stress and anxiety seems to be the important factor. It's certainly an important factor for me. So if you're having a tough time, ease back on the training.
Social pressures can be a factor, a little competition is fun and motivational but I've learned the hard way that I train better and I'm less likely to overdo things when I'm on my own. If I'm climbing with someone better, younger, or more female I have to be particularly careful! Don't know if this applies to you but it's worth considering.
Age is an important. Don't get older but, if you can't avoid this, don't be in your early-mid 20s when suddenly you are no longer completely invulnerable. Especially don't be in your mid-late 30s. Performance starts to deteriorate then so you have to train harder or start training or try harder to maintain performance. At the same time you're becoming more injury-prone but have not yet worked out strategies to work around this. Lots of climbers get injured repeatedly and give up, adopting some face-saving activity like surfing, cycling, running a business, becoming a parent, or - if really desperate - fell-running. This is when self-assessment is particularly important.
The biggest physical risk factor for me is lack of sufficient recovery time, this is very age-related. Two days a week on plastic is now my limit. The other is lack of training variety. I have to mix things up, either climbing variety or by including some non-climbing training. This is usually dressed up as 'working the antagonists' or some such notion. I think the main thing is to do something else. Other factors that seem to apply to me: dehydration, lack of sleep, and not stopping soon enough if training strength or power.
At the end of it though, some people are more injury-prone than others and often it's just a case of 'shit happens'.