It can be due to hypertension,Gastroesophageal reflux disease(do you have heart burn and difficulty in swallowing) and hiatal hernia, disorders involving the lung like
Pneumonia,
pulmonary embolism, pneumothorax etc;cardiac diseases, lung cancer, thoracic outlet syndrome,pancreatitis,gall bladder disease(fullness and pain in the right side of abdomen and chest after eating a greasy or fatty meal) and muscle pain[costochondritis(an inflammation of the joints in your chest)].