There can be multiple reasons for this. It is not unnatural if you are diabetic. Other reasons can be DVT. I would advise you to get a blood
sugar test done and consult a endocrinologist.
Next Steps
if blood
sugar is normal then consult a surgeon for surgery. he might suggest colour Dopler test for your lower legs.
Health Tips
when you sleep at night keep pillow under your legs. raise them up and do not do a lot of walking