A young man repos chest pain retrosternal over last few hours. Pain is not related to . and relieved significantly on sitting and forward. Likely possibility is -
Acute pericarditis is a type of pericarditis (inflammation of the sac surrounding the hea, the pericardium) usually lasting less than 6 weeks. It is the most common condition affecting the pericardium. Ref Davidson 23rd edition pg 525
Angina pectoris
Acute pericarditis
Reflux esophagitis
Rib fracture
Miscellaneous