Not Sensitivity. Pedal edema can be caused by many things. Some examples are: systemic conditions (one of the most well known is congestive heart failure), lymphedema, venous stasis, gravity when people stand for long periods, water retention from an increase in salt intake and many other causes. If this is affecting you, if is best to start with a visit to you primary care physician for an evaluation.
It can be. Salt can certainly creat swelling of the feet. If it is persistant you need to see a doctor.