Hello. Thank you for asking at HCM. I went through your son s history. From your history, both allergic and non-allergic causes are possible. I would like to make following suggestions to you: 1. Were I treating him, I would prescribe a combination of montelukast and levocetirizine for at least 2-4 weeks (depending upon response). 2. I would like to ask his symptoms in detail. e.g., Has he ever had wheezing? does he have cough? During what time of the day he has maximum symptoms? Does anyone of his family members have allergy? What are the medications he is taking? etc etc. 3. I would also like to prescribe him a course of vitamin C for at least 4 weeks. It helps in reducing common cold episodes. 4. I would suggest you to consult an Allergist-Immunologist who will advise him allergy testing so that you can know whether he is allergic or non-allergic as well as if allergic, what are the substances he is allergic to. 5. I would suggest not to smoke at home if anyone in your family smokes. Also, please try to avoid exposure to dusts, smokes and air pollution to your son as much as possible. 6. A nutritive diet rich in vitamins and minerals (e.g., adequate green leafy vegetables, fruits, sprouted beans, etc) will be helpful in long run. 7. Some medications used in cough syrups can cause heart running fast. So I would like to review his medications. 8. Pain in chest at 4 years of age is usually not due to heart-related cause. Personally I would consider muscular pain or gastritis first. In that case, paracetamol for muscular pain and antacids for gastritis will be enough. So please do not worry about heart condition at present. 9. Of course, if by listening to his heart sounds via stethoscope one thinks there is a possibility of heart disease or if he has any of the following symptoms, I would suggest Echocardiography to diagnose/rule out cardiac cause: breathlessness after walking/running, bluish discoloration of lips/nails, swelling of the feet, etc. Hope above answer will be helpful to you. Wish your son the best of the health. Should you have any query, please feel free to ask at HCM. Regards.