Typically, pleuritic pain is a stabbing sensation aggravated by breathing and coughing, but it can vary. It may be only a vague discomfort, or it may occur only when the patient breathes deeply or coughs. Pain is usually felt over the pleuritic site but may be referred to distant regions. Irritation of posterior and peripheral portions of the diaphragmatic pleura, which are supplied by the lower six intercostal nerves, may cause pain referred to the lower chest wall or abdomen and may simulate intra-abdominal disease. Irritation of the central portion of the diaphragmatic pleura, innervated by the phrenic nerves, causes pain referred to the neck and shoulder.
Respiration is usually rapid and shallow.
Motion of the affected side may be limited. Breath sounds may be diminished. A pleural friction rub, although infrequent, is the characteristic physical sign. It need not be accompanied by pleuritic pain, but it usually is. The friction rub varies from a few intermittent sounds that may simulate crackles to a fully developed harsh grating, creaking, or leathery sound synchronous with respiration, heard on inspiration and expiration.