Hi,
Welcome to the ehealthforum and I am really glad to help you out.
One of the possibilities for your symptoms is rheumatoid arthritis. It may cause stiffness and pain with movement. Over time, deformity of the fingers may occur. Diagnosed by ESR and Rheumatoid factor in blood. But the best test for confirmation for rheumatoid arthritis is antiCCP antibody (anti-cyclic citrullinated peptide antibody) which is the latest and most confirmatory test for rheumatoid arthritis.
You should consult a rheumatologist and get it evaluated.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care.