What is pleurisy? what are the symtoms of pleurisy? how do you get pleurisy?

Let me explain: A double layer of membranes called pleura separate your lungs from your chest wall. When inflamed, the two layers of the pleural membrane of your chest rub against each other like two pieces of sandpaper, producing the pain of pleurisy when you inhale and exhale. Many things could cause it. Flu, pneumonia, tuberculosis, clot in the lung, injury to chest and cancer. Some time could be unknown.