Can thyroid and poly cystic ovarian syndrome cause ankles to swell?

Possibly. Hypothyroidism can cause swelling and fluid retention. Pcos causes weight gain, but not fluid swelling. However, if your thyroid levels are normal, i would look for a different cause for the swelling. In your age group, the most common causes would be varicose veins, weight related swelling, and/or excess salt intake.