As you intimated--this is called "Trigger Finger", though the clinical term is:
TENOSYNOVITIS. This great link lists all the answers to your Qs, and then some:
In terms of treatment, try: [from same article]
If you've tried the above for 1-2 wks and there's no improvement, then you need to see an Orthopedist or Hand Surgeon to consider the following treatments:
NOTE: Usually the steroid injection is curative--I've received steroid injections [in the past] for 2 separate cases of trigger finger [2 different fingers]: each injection CURED the problem within 24 hrs after 1 injection.
Good luck & take care.
I hope you found this to be helpful-IF SO, please hit **ACCEPT** as you read this Answer. (Positive Feedbacks and Bonuses appreciated also). THANKS !
(also-you can ask a followup Q, if you need to). "CHAT" is available too.
Best Wishes for your Health,
--Dr. Steve, M.D./FABFP