Hi Marianne Jane - I was on Tamoxifen for 18 months (post surgery and chemo) and this did not cause me any swelling of my hands. I'm wondering if it's possible your swelling could be lymphodoema? (If you had surgery and any nodes removed?) I'd suggest a visit to your Oncologist or GP would be a good idea - then at least you can find out and put your mind at rest. I had a little joint stiffness while on Tamoxifen, but not a lot. Much more joint stiffness since changing to Femara. Good luck - hope the swelling abates for you. Kym :)