Why are my fingers swollen every morning?

Edema or inflammatio. Several causes including but not limited to heart related, kidney related, heart failure, liver issues but it is a vague symptom and may not be anything serious.
Many possibilities. This depends on how the fingers are swollen. It could be the joints, the tendons or just soft tissue swelling. I can't be certain in your case which it is. We see people with morning stiffness and swelling with inflamatory arthritis like rheumatoid arthritis. I can tell if this is your problem and you need to see your physician who may send you to a rheumatologist.