According to Dameshek, true polycythemia (polycythemia vera: PV) is a chronic myeloproliferative disorder of the total bone marrow without any evidence of invasiveness, in which erythrocytosis, leukocytosis, and thrombocytosis are all simultaneously present.
However, in patients suffering from connective tissue disease or lung cancer, chest pain may persist for long periods. What Causes Pleurisy? Pleurisy may occur inhealthy, young people who have an infection in the lungs caused by bacteria or virus. Pleurisy may last a few days or up to two weeks. In rare cases, the infection may spread, causing pleurisy in other people. Pleurisy may also be associated with air leaking in the pleural cavity from a punctured lung, a condition called pneumothorax.
Pleurisy occurs when the pleura becomes irritated and inflamed. As a result, the two layers of the pleural membrane rub against each other like two pieces of sandpaper, producing pain when you inhale and exhale. The pleuritic pain lessens or stops when you hold your breath. Causes of pleurisy include: A viral infection, such as the flu (influenza)