Swelling, stiffness, aches and pains in the fingers may well be due to other problems, and may persist to some extent following any form of treatment. Many patients with trigger fingers also have a tendency to have swelling, stiffness and soreness of the moving parts of their hands, and that is not changed by surgery. With this in mind, the great majority of patients are improved with appropriate treatment. It depends on how much it is bothering you - it really is a quality of life issue. This is not a problem which can spread to other parts of your body.
Some people have triggering which resolves over a period of months.
Other than persistent pain and stiffness, the additional problem which may develop is a permanent partial bend of the middle joint of the finger. This is more likely the longer triggering has been going on. The main reason to do surgery is to relieve pain. Some people will have a mild problem which flares up from time to time, and treat it themselves or ignore it. Others will have a severe problem which prevents them from doing many things with their finger, and feel that they have no choice but to have surgery.