Hi Thanks for posting on HCM Swelling in foot may be caused by many medical conditions.Some of these causes may include: -Foot or ankle injury(stress/strain/sprain) -Soft tissue infections like erysipella, cellulitis, myositis -Achille s tendinitis -Osteoarthritis -Blot clot in vein -Renal, liver or heart pathologies even though in most cases swelling will be bilateral and associated with other symptoms. -And other causes. I will suggest you see the Doctor for examination as only a keen medical examination may help to identify the cause since your description of symptoms too not very clear.You may however try the following: *Take a pain/antiinflammatory drug like ibuprofen if pain *Elevate leg while lying *Avoid stressing the leg/rest -A diuretic like lasilix may also help if swelling too serious *The see the Doctor for examination and investigation. Hope this will help Best regards