<P> The most common cause is a viral infection . Other causes include pneumonia, pulmonary embolism, autoimmune disorders, lung cancer, following heart surgery, pancreatitis, chest trauma, and asbestosis . Occasionally the cause remains unknown . The underlying mechanism involves the rubbing together of the pleurae instead of smooth gliding . Other conditions that can produce similar symptoms include pericarditis, heart attack, cholecystitis, and pneumothorax . Diagnosis may include a chest X-ray, electrocardiogram (ECG), and blood tests . </P> <P> Treatment depends on the underlying cause . Paracetamol and ibuprofen may be used to help with the pain . Incentive spirometry may be recommended to encourage larger breaths . About one million people are affected in the United States each year . Descriptions of the condition date from at least as early as 400 BC by Hippocrates . </P> <P> The defining symptom of pleurisy is a sudden sharp, stabbing, burning or dull pain in the right or left side of the chest during breathing, especially when one inhales and exhales . It feels worse with deep breathing, coughing, sneezing, or laughing . The pain may stay in one place, or it may spread to the shoulder or back . Sometimes, it becomes a fairly constant dull ache . </P> <P> Depending on its cause, pleuritic chest pain may be accompanied by other symptoms: </P>

Pain left side of chest when breathing deeply