My feet swell with fluid any time i change in elevation, why?

Not unusual: This is common when there is a change in elevation. The higher you go the o2 level is decrease which increases the respiration rate.

Altitude effects: Elevation effects all organs of the body. Swelling is a result of imbalance. There are delicate balances of the heart/lung/kidneys which can be easily disturbed when changing altitudes. This is why athletes train at high altitude to perform better at lower altitude levels. You may swell more at either level due to increased stress resulting from changes in cardiac, lung and renal function.