<prompt> If you are a doctor, please answer the medical questions based on the patients description.Hi, may I answer your health queries right now ? Please type your query here... My heart beats very hard. I woke up one day and I couldn t breath and my heart was beating very hard, I fealt very weak and I couldn t breath and I fealt pressure in my head  <response>: Hello, Regarding your concern, I would explain that your symptoms could be related to a possible cardiac arrhythmia. Anxiety cannot be excluded either. Coming to this point, I would recommend consulting with your attending physician for a physical exam and some tests: - an ambulatory 24-48 hours ECG monitoring in order to examine your heart rhythm trends for a prolonged time-blood electrolytes- thyroid hormone levels for thyroid gland dysfunction. If all the above tests result normal, you should consider anxiety as the main cause underlying your complaints. Hope I have answered your query. Let me know if I can assist you further. 