In reply to Fenda:
My feet rarely slip climbing (thank you shoes, technique, lack of confidence and belayshonship) but I've had similar injuries through my sport history having kept several huge naughty equines! Each of my wrists have been broken multiple times in different places (thankfully, so I've avoided surgery).
Recently I've had a 'sprain' so I've used a support or bandage (equivalent of vet wrap for animals) which has proved effective.
I'm not a fan of rest: I don't know the meaning of it without a breakage: so support and tentative nursing / not over pushing it has helped.
Does it feel like a tendon or a muscle? Tendons are REALLY painful (my mom is trained (a nurse and sports physio) so knows and advises me frequently). Tendons are often as debilitating as breaks as a rule of thumb.
Any history of carpal tunnel or rsi?
Supports help me and sighting it reminds me I'm gonna feel it onsighting a sport route if I push it. Depends how you feel; if the pain extends to the wrist, support and continue GENTLY. If it's just finger - my netball days say tape up, and rest.
You may still be able to climb or Boulder some routes using different technique or routes.
Edit: punctuation. Naughty me!
Post edited at 22:53