Hi. I Am A 45 Yr Old Female. I Have

Hi. I am a 45 yr old female. I have had high cholesterol for a few years now and hypothyroidism. Recently I have been having a feeling in the left side of my neck that feels like something is blocking the blood flow. It isn't there all the time. I also have this strange sensation like something is going through my veins of my legs and arms. It comes and goes. What could this be ?