Hello, As you mentioned your husband is diabetic I wish to know if he has any high blood pressure? As welling in lower limbs especially the foot can be due to lack of venous return. That means that due to muscle weakness and lack of physical exercise it leads to swelling. the pain can be due to this as well. Can please check some signs of varicose veins? Like, change in skin colour from hip till ankle joint. Swelling and pain can also be because of this. Please get it examined once if you notice it. For this issue of pain and swelling, I will recommend first to dip the foot in the hot water. Keep it elevated over the pillow while lying down. do ankle toe exercise in the same position. Next, you need to control your diabetes. What is the Reading of HbA1c? is it under control if not then need to work out behind the proper medicine and also do regular physical exercises. Exercise can help control blood sugar levels by burning calories. In fact, I should share this practice of mine with you. I need to see a lot of diabetic cases having issues and with a proper combination of drug and exercise, they perform well. In fact, now most of them have got rid of drug and only exercise off late they are doing. Hope I have answered your query. Let me know if I can assist you further. Take care Regards, Jay Indravadan Patel, Physical Therapist or Physiotherapist