Why do my feet feel sore and swollen at night?

Varicose veins? If you have veins that you can see in your legs, think about seeing a phlebologist (vein specialist). If you don't see any veins, you could try wearing compression stockings during the day. If that helps, i would still see a phlebologist. If no veins and stockings don't help, a visit to a podiatrist might be in order. Seeing your primary care doctor before anyone else is never a bad idea.