Hello dear, Thank you for your contact to health care magic. I read and understand your concern. I am Dr Arun Tank answering your concern. Such fainting attacks can develop sometimes. But there is nothing to worry if the consciousness regains immediately. You can get your ECG done. This will tell us any of the problem if you have. If the ECG is normal nothing much to worry. But if you develop same episode more times than you should get your self examined in detail. Some times while running or walking we may give extra burden to the heart which can t work for more duration this will complicate as a unconscious ness. You can give some rest to your heart while running and you can avoid such incidents. I will be happy to answer your further concern on bit.ly/DrArun. Thank you, Dr Arun Tank Infectious diseases specialist, HCM