Donna Colucci, age 14, of Reno, Nev., for her question:

WHAT CAUSES PLEURISY?

Pleurisy is an inflammation of the pleura membrane that lines the chest cavity and contains the lung. Most cases are due to infection and many are associated with pneumonia in the underlying lung.

Some cases of pleurisy are due to viral infections. Occasionally pleurisy may occur in other diseases such as tuberculosis, systemic lupus erythematosis, rheumatic fever and kidney failure. Pleurisy may also develop in conjunction with a blood clot on the lung or it may be associated with the development of fluid in the pleural space between the chest wall and the lung.

The characteristic symptom of pleurisy is a sharp pain brought on by breathing and coughing. The patient breathes shallowly.

Treatment of pleurisy attempts to cure the underlying disease causing it. The pain is usually controlled by a prescribed analgesic drug.