The duration of pleurisy pain is about 7-10 days, with different time differences in different patients. Pleurisy pain is due to fluid inflammatory exudation from the pleura, which causes the wall and dirty layers of pleurisy to rub against each other, especially when breathing, moving, and violently turning over, increased friction will aggravate the pain. If the inflammatory exudation improves quickly after treatment during the disease treatment, the friction will naturally decrease and the pain will be reduced. As the disease worsens, the pleura not only inflammatory exudate pleural fluid, because the pleural fluid exists, separating the pleural dirty layer and the wall layer, despite breathing and activities, the pleural dirty layer and the wall layer do not appear friction, the pain will be reduced. So pleurisy chest pain is relieved mostly in about 7-10 days, but it is important to distinguish whether pleurisy is getting better or aggravated to produce pleural effusion. So at this time, even though pleurisy is not painful, it is necessary to determine whether there is no pleural fluid or an increase in pleural fluid, and to let the doctor determine the next step of treatment based on clinical manifestations, imaging tests, and ultrasound.