<s>[INST] Hi I went to the doctor yesterday with chest pains and trouble breathing when I stand up. I have to lay on my back to breath the most air in but it hurts to take a full breath and when I stand up I start hyperventilating because I can barely breath and I went to the doctor my heart rate was 132 when it s suppose to be around 80 (I m 12) do you know what s wrong? [/INST] Thanks for your question on HCM.I can understand your situation.In my opinion you should get done ECG first to rule out cardiac cause for your symptoms. As tachycardia (rapid heart rate) and breathing can be seen in cardiac cause.If ECG is normal than no need to worry for cardiac cause.Bronchitis can also cause breathlessness and tachycardia. So get done PFT (pulmonary function test) to rule out bronchitis.If all of the above investigations are normal than mostly you are having anxiety mostly.So avoid stress and tension. Be relax and calm.Consult psychiatrist and get done counseling sessions. Don't worry, you will be alright. </s>