If you are experiencing a true panic attack, then it is not dangerous, and can't harm you. However, if you are experiencing a panic attack from an underlying medical condition, such as cardiac problems (coronary artery disease), breathing problems (asthma), or a thyroid problem, then these medical conditions, if left untreated, can be harmful. The only way to find out if your panic attacks are due to a medical condition is to get a full history and physical from your doctor. Then the doctor can order laboratory tests to see if you have any of these medical conditions, such as an ECG (electrocardiogram) for heart problems, and bloodwork to assess your thyroid levels.
