What Causes Lighteadedness?

I am 57 yrnold female,diagnosed hypothyroidism,after three in conclusive biopsies,I had half my thyroid removed along with a leg nodule,all were benign. The procedure was four days ago. I will remain on same dose of synthroid until new blood work is taken in three weeks. My question to you,is that I am light headed,despite not taken any pain meds.is this normal? Will be seeing the surgeon in a few days to have stitches removed,don't like this feeling.