2 years ago I was diagnosed with Hashimoto s thyroiditis, I also have a small cyst on my thyroid gland.today in the mirror I noticed while I was speaking with my mom, the longer that I spoke the more swollen my common carotid arteries had become, both sides. as soon as I stop speaking the swelling goes right back down, what has me curious and a little nervous is how much and how fat they swell up.is this something that should concern me I m already in and out of the doctors with these issues.I have a primary care and I follow up with my endocrinologist once a year, she does a CAT scan on my thyroid and I do have 2 small pineal cyst at the pituitary gland therefore I do have an MRI of the brain yearly. if this is a common side effect I will ignore it but my father did have thyroid cancer in the early 70s and I don t know if this is something I should go back to my endocrinologist for.