Swelling of feet and toes on both the sides can be associated because of the following reasons;
1) Venous valvular incompetence
2) Obstruction of the lymphatic outflow
3) Dependent edema which can occur because of the prolonged standing or sitting.
4) Congestive heart failure
5) Kidney diseases
6) Protein deficiency
It is always important to discuss this with your primary care physician for the evaluation and investigations. Dependent edema because of long activity on feet may be the most likely reason in your case. This goes off in 72 hours. Following measures would be helpful;
1) Avoid prolonged standing or walking for long distances in a single stretch.
2) Whenever you sit; keep your legs elevated on a chair or a sofa or stool. Do not hang the legs, otherwise gravity will increase the swelling.
3) Exercises / physical therapy
a) Lie down straight and raise your leg and feet for 10-20 seconds. Repeat this for ten times (twice a day whole set).
b) When you sit; pull the feet towards you for 10-20 seconds. Repeat it for ten times twice a day.
4) Raise leg end of your bed by 6 inches.
Please feel free for your follow up questions.
I would be happy to assist your further, if you need any more information.