How common are rock climbing injuries?
Rock climbing injuries can be quite common, but it depends on the climber and how well they listen to their bodies, and if they give their body the adequate amount of rest it requires.
It's quite common for new climbers to get injured to some extent due to them putting too much strain on their bodies and tendons, and due to them not resting enough and allowing their body and tendons to heal.
Even if you have been exercising in the gym, lifting weights, or doing other types of sports, climbing involves muscles that most people normally do not use, which means, they are not as strong as other muscles in the body. Due to this, new climbers often find "new" muscles in their body that they didn't know existed and never felt. It's because these muscles, that normally are not used, have been used more heavily during climbing, and since they are weaker than the other muscles to a greater degree, they are put under a much higher level of strain, resulting in possible overuse.
In addition to muscles, though, tendons also need time to adjust to the new strain that is put on them. Specifically, the tendons in the fingers and arms. A very common injury that occurs in new climbers are pulley injuries. One of the main reasons they happen is because new climbers tend to not know that these are in fact tendons, and not muscles. They are very different, and the amount of strain you can and should put on them is different, including the amount of rest they need.
Climbing involves more than just your muscles, which is why, adequate amount of rest is required in order to make sure that your body is healed, including muscles and tendons. Otherwise, it can be very easy to injure yourself.