No pleural friction sound is normal, pleural friction sound is mostly due to pleural inflammation, a large number of fibrin deposits lead to the pleura become rough, deep breathing due to friction can be heard pleural friction sound, while the normal is not heard.
The visceral and wall layers of the pleura are lubricated by about 5 to 15 milliliters of colorless, transparent fluid. The area where the fluid exists is called the pleural cavity, which lubricates and protects the wall and the viscera, preventing damage caused by repeated friction between the two with frequent breathing. The fluid maintains an equilibrium in the pleural cavity and protects the body. In healthy people, there is no pleural friction due to the presence of a small amount of pleural fluid in both the visceral and mural pleura for lubrication.
Pleural friction sounds are common in patients with exudative pleurisy, tuberculous pleurisy, and neoplastic pleurisy. It is recommended that the primary disease can be diagnosed by chest X-ray, CT examination, bronchoscopy and thoracoscopy, ultrasonography, electrocardiography and other examinations.
If you feel strongly uncomfortable promptly go to the regular hospital, and under the guidance of the doctor for appropriate treatment.