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Since you are 31yrs better get a ECG done to rule out cardiac cause of chest pain
.It is not likely but to be on safer side.Secondly you smoke 8-10 cigarettes/day which can cause discomfort in chest & stomach due to hyperacidity
.Please reduce or if possible stop smoking
.Do a ECG to rule out cardiac cause;if it is abnormal consult a Cardiologist
.Lastly you take a tablet of Ranitidine-300mg twice a day & see it should give you relief.If the pain persists please consult a doctor.