The degree of clarity is an indicator of infection, cancer, or other conditions that may be causing the buildup of fluid or blood in the pleural space. Biopsy
If tuberculosis or cancer is suspected, a small piece of the pleura may be examined under a microscope to make a definitive diagnosis. This is called a biopsy. Several approaches to taking tissue samples are available               

Insertion of a needle through the skin on the chest to remove a small sample of the outer layer of the pleura
Insertion of a small tube with a light on the end (endoscope) into tiny cuts in the chest wall to visualize the pleura, and biopsy of small pieces of tissue through the endoscope
Removal of a sample of the pleura through a small cut in the chest wall (open pleural biopsy), usually done if the sample from the needle biopsy is too small for accurate diagnosis

Treatment
Treatment has several goals:
Relief of symptoms
Removal of the fluid, air, or blood from the pleural space
Treatment of the underlying condition

Procedures
If large amounts of fluid, air, or blood are not removed from the pleural space, they may cause the lung to collapse. The surgical procedures used to drain fluid, air, or blood from the pleural space are as follows:

During thoracentesis, a needle or a thin, hollow, plastic tube is inserted through the ribs in the back of the chest into the chest wall. A syringe is attached to draw fluid out of the chest.
Sometimes, it becomes a fairly constant dull ache.Depending on its cause, pleuritic chest pain may be accompanied by other symptoms:
Dry cough
Fever and chills
Rapid, shallow breathing
Shortness of breath
Fast heart rate
Sore throat followed by pain and swelling in the joints

Related problems
Pleurisy is often associated with complications that affect the pleural space. Pleural effusion
In some cases of pleurisy, excess fluid builds up in the pleural space. This is called a pleural effusion. The buildup of excess fluid, will more often than not force the two layers of the pleura apart so they dont rub against each other when breathing. This can relieve the pain of pleurisy. A large amount of fluid can result in collapse of the lung. This can make it difficult to breathe. In some cases of pleural effusion, the excess fluid becomes infected and turns into an abscess. This is called an empyema. Pleural effusion involving fibrinous exudates in the fluid may be called fibrinous pleurisy, which sometimes occurs as a later stage of pleurisy. A person can develop a pleural effusion in the absence of pleurisy. For example, pneumonia, heart failure, cancer, or a pulmonary embolism can lead to a pleural effusion. Pneumothorax
Air or gas also can build up in the pleural space. This is called a pneumothorax. It can result from acute lung injury or a lung disease like emphysema. Lung procedures, like surgery, drainage of fluid with a needle, examination of the lung from the inside with a light and a camera, or mechanical ventilation, also can cause a pneumothorax.