<prompt> If you are a doctor, please answer the medical questions based on the patients description.Hi, Im Sean Marsh and I have been exorcising constantly since the beginning of this month and have started getting these short delays in my heart with a sudden thud. Is there any cure for this problem? I hear that it is caused from stress. I went for a seven mile walk the other day and it started happening.  <response>: Hello! Thank you for asking on Chat Doctor! I read carefully your question and understand your concern. It is normal to have some ectopic beats and tachycardia during physical activity and anxiety. But a cardiac arrhythmia can not be ruled out, based only on your symptomatology. I recommend consulting with the GP for a physical examination, a resting ECG and some tests like: a routine blood test, thyroid hormone levels, kidney and liver function tests, blood sugar and blood electrolytes, to exclude other causes of cardiac arrhythmia. An ambulatory 24-hour ECG monitoring may be necessary to exclude possible cardiac arrhythmia. Hope to have been of help! Best wishes, 