I am a 69 year old male runner, 6 miles,
Could be due to Varicose veins.
Hi, I am Dr Gopal Goel, Orthopedic Surgeon.
I have read the question and in my opinion, the first possibility would be varicose veins in the legs causing dependant oedema, which appears as swelling in the foot, since there is no history of injury to the foot.
Hence I'd suggest that you wear below knee compression stockings for 2-3 weeks to see if the swelling disappears.
If the result is not satisfactory then you will need to be examined by an orthopaedic surgeon to decide the further course of action (which may include a Doppler scan of the lower limb).
Thank for the question.
Please feel free to ask any other question.