My wife's feet and lower legs are quite swollen- why?

Few reasons: Is it possible your wife is pregnant? That could be a reason, sometimes medication side effects can cause this. Does she have varicose veins? Any issues with high blood pressure or cardiac issues? Does she eat a lot of salt? Any new finding such as the one you describe should always be checked out by your internist.

High blood pressure: This may be due to high blood pressure or pregnancy. See your primary care doctor to have this further investigated.