Hmm -
I know when my foot swells up it usually due to my arthritis acting up or from my heart problems starting to stir, therefore, my body will hold water around the ankles causing the foot and surrounding area to swell.
If it keeps on happening...... I would make an appt with your GP to make sure all is well, and to get some Lasix pills if needed to decrease the water retention in the body.
LoVe,
Rhapsody -