The chest pain can be due to various reasons:
*Musculoskeletal- Rib-fracture,myositis of pectoral muscle,vertebral collapse, costochondritis etc.
*Cardiac- ischemic heart disease, pericarditis,infective endocarditis, cardiomyopathy, valvular heart disease,aneurysm of aorta etc.
*Respiratory- Pleurisy,pneumothorax, pulmonary hypertension,embolism,infection,malignancy etc.
*Functional
*Miscellaneous- Herpes zoster of intercostal nerves,oesophagitis,pancreatitis,peptic ulcer,splenic flexure syndrome, cholecystitis etc.