<s>[INST] Hi. I m a 19 yr old female. For about 3 or 4 years I ve been having this problem. First I feel like all my blood rushes to my head &I get light headed &feel butterflies . Then my heart starts beating fast. I don t just mean fast as in just ran a half mile but probably double that. Like 5 or 6 beats per second. You can see my chest beating. I ve had other people feel it as well. It also gives me very sharp pains in my chest. It hurts to breathe or swallow. It feels like there is a truck tire sitting on my chest. Then it just stops. Not gradually. Just instantly stops. This happens very randomly. I could be working or lying down or folding laundry. I ve been to the hospital multiple times&they ve never found anything wrong. I need to know what s wrong. [/INST] Thanks for your question on Chat Doctor. I can understand your problem and situation. In my opinion you are having anxiety mostly. Your age is too young (19) for cardiac issues. But better to rule out cardiac cause first. So get done ECG. If ECG is normal than no need to worry much. Another possibility is anemia and thyroid related problems. Because in both these conditions palpitation and flushing of head is seen. So get done CBC (complete blood count) and thyroid function tests. If both are negative than it is anxiety only. So consult psychiatrist and get done counselling sessions. Try to identify stressor in your life and start working on its solution. Avoid stress and tension. Be relax and calm. </s>