It is normal to have some swelling after an injury. But if a
large area of swelling occurs within 30 minutes of an injury, the swelling may
be a sign of:
A more serious injury.
Swelling (edema) in the feet and ankles is common after you have been
sitting or standing for a length of time. It is also common during hot or humid
weather. Sitting or lying down with your feet propped up often relieves this
type of swelling.