Pleurisy: An inflammation of the visceral and parietal pleurae that line the inside of the thoracic cage and envelop the lungs, pleurisy usually begins suddenly.
Cause: Pleurisy develops as a complication of pneumonia, tuberculosis, viruses, systemic lupus erythematosus, rheumatoid arthritis, uremia, cancer, pulmonary infarction, or chest trauma.