Hi Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concern.
Chest tightness is a very serious symptom. Your overall checkup should be done.Your problem may suggest these conditions
1. Gastric problems like gastritis, GERD, may seem like
heartburn or burning sensation in chest, pain in sternum etc. This will relieved somewhat by taking antacids
2.
Angina pectoris / heart attack- this might be symptom of heart problem like angina pectoris / heart attack.In that case you will have tightess in chest, difficulty in breathing, pain in left side of chest radiating in hand or jaw.
3. Lung diseases like pneumonia,
pneumothorax can also cause these type of symptoms.
Heart problems would be diagnosed bu EKG, However in case of
stable angina EKG can also be normal & TMT test or echo may be required.
Hope your query is solved
Get well soon