So this has been happening for a month or two now when ever my head is bent down below my heart there's a sudden feeling like blood is rushing to my head I get super hot and start to sweat profusely and when I lift my head back up I still feel hot and sweat for a while after. I only sometimes get dizzy from it I feel like I have to hold my breath and it happens every time my blood pressure is 120/80 my blood sugar is normal I'm 26 female and it also causes me to get a headache and very uncomfortable pain that lasts up to a few hours. Could this be caused by my thyroid?