<s>[INST] Today, while my 4 yr. old son was at school he started complaining of chest pains and holding his chest. He was screaming in pain according to his teachers. This went on for about 3-4 min. and then went away. He was born at 26 weeks premature and weighed 2lb. 2oz. He did have a slight heart murmur when he was a baby, but he is perfectly healthy now. What could it be? [/INST] Thanks for your question on Chat Doctor. I can understand your concern. It is very difficult to assume diagnosis in child Chat Doctor.  He is premature and had heart murmur, so we should definitely rule out heart and lung related diseases for his chest pain. So consult pediatrician and get done 1. ECG and 2d echo to rule out heart related causes. 2. Clinical examination of respiratory system and chest x-ray to rule out lung related causes. If all these are normal then no need to worry about major heart or lung related diseases. Simple musculoskeletal pain can be the cause for his symptoms. So give him painkiller syrup and apply warm water pad on affected areas. Don't worry, he will be alright but first rule out heart and lung diseases. Hope I have solved your query. I will be happy to help you further. Wishing good health to your son. Thanks. </s>