There are numerous things that can cause foot pain. the most common being plantar fascitis (fallen arches) It really depends upon where the pain is. Could also be heal spurs.
When my feet hurt its usually because the shoe I wear doesnt have enough arch support. Another reason is that the soles of my shoes arent padded enough.
Assumed that you have not been walking over glowing charcoal, your shoes may be responsible for your pain. Maybe you should consider consulting a doctor.