<s>[INST] I am 34 years old, and 2 out of 3 days I have experienced a tightness in my chest where my heart is beating hard and fast for about 45 seconds or so then goes back to a normal rythym and I feel like I'm having trouble breathing during that time. After this is over I get a headache within 20 minutes or so. I am also experiencing some minor aches in my shoulder and left armpit. Is this something serious? [/INST] Thanks for your question on Health Care Magic. I can understand your concern. Yes, all these symptoms can be due to serious illness like arrhythmia (rhythm disturbances in heart). So better to first rule out arrhythmia in your case. So get done ecg, 2d echo and Holter monitoring (24 hour continuous monitoring of ecg). If all these are normal then no need to worry for arrhythmia or other heart diseases. Sometimes stress and anxiety can also cause similar symptoms. So avoid stress and tension, be relax and calm. Consult psychiatrist and get done counselling sessions. Try to identify stressor in your life and start working on its solution. Along with counselling, anxiolytic drugs are also beneficial. Don't worry, you will be alright. But better to first rule out arrhythmia. Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks. </s>