last couple days my right index finger tip gets very slightly tingly once in a while. no other fingers -- only my right index.
I get this regularly. I am pretty sure it's due to poor peripheral circulation.
I think the body either reduces peripheral circulation to the toes and fingers, or it's just that circulation is poor in those areas. The next step past the tingling is lack of feeling and numbness in the fingers. You can see the affected finger(s) are distinctly yellowish due to the poorer blood flow. You may also notice the affected finger is colder to touch.
My interpretation is that medication (esp blood pressure lowering) contributes to the problem. Exercise too, where the heart pumps more blood (preferentially) to the exercising muscles can produce this numbness and tingling.
Longer term, I think a good exercise routine will help reduce the effect.