Sometimes,on days i am on my feet the whole time,my ankles look a little puffy. my doc said it's nothing,but what could be causing it? it doesn't hurt

Gravity: Hi. Yes, gravity is the culprit when you stand long periods without walking. When you walk, the leg muscle action in conjunction with the valves in the veins in the legs, move blood up against gravity to return to the heart. But when you stand without walking, that mechanism is not operating and thanks to Isaac Newton (and Einstein: general relativity), blood accumulates in the lower extremities.

WATER: Our bodies are basically a tower of water. When we sit everything is fine but if we stand up the water goes to our feet by gravity, Add a tiny amount of varicose veins and you now see why it is to be expected.