Thanks for your query.
Your finger joints pain could be due to Rheumatoid arthritis
(RA), systemic lupus erythematosus
(lupus), psoriatic arthritis
, osteoarthritis (OA), Infectious arthritis
or crystal deposition arthritis
To pinpoint the diagnosis, complete physical examination and investigations like complete blood counts, ESR, RA factor, CRP, serum uric acid, serum creatinine, X-ray and MRI joints from a rheumatologist/ orthopaedician are needed.
You can take Vit.D and calcium supplements. Pain killers like Indomethacin 25mg can be taken to reduce stiffness and pain. Routine physical activity is always advised as this will prevent stiffness from aggravating.
I do hope that you have found something helpful and I will be glad to answer any further query.