Pleurisy affects the membranes that line the chest cavity and around the lungs. These 2 layers of membranes are separated by a thin layer of fluid that allows them to move smoothly by one another with each breath. If the membranes swell, they rub against each another, causing sharp pain when breathing and/or coughing. This symptom/condition is called pleuritis or pleurisy. Usually, there is no pain between breaths. More symptoms may involve shortness of breath, dry cough, or fever/chills.
Pleurisy is not a disease by itself--it is a symptom of another condition, such as viral infection, bacterial infection (i.e. pneumonia or tuberculosis), or an auto-immune condition (like lupus or rheumatoid arthritis). As such, pleurisy is not contagious, BUT some of its possible underlying conditions, such as tuberculosis, can be VERY contagious, especially to young children and people with low- or non-functioning immune systems (from AIDS, MDS [not muscular dystrophy, but myo-dysplastic syndrome], Leukemia, etc.).
In addition to being caused by sickness, pleurisy can also show up after a chest injury or heart surgery. Occassionally its cause is undetermined. To try to diagnose the underlying cause, physicians may listen to the lungs with a stethoscope, look at an X-ray, run blood tests, and/or remove a fluid sample from the chest with a needle.
The symptoms of pleurisy can be diminished by treating the underlying cause. Bacterial infections can be treated with antibiotics, non-steroidal anti-inflammatory drugs can be used to help symptoms in the case of viral infections, which are usually left to run their course. Codeine can be used to diminish coughing and pain.
As a possible complication of many illnesses, pleurisy can be chronic or reoccur, with different levels of severity. Persons with severe chest pain that goes away when they hold their breath, or go along with a fever, may want to see their doctor to diagnose possible pleurisy and any other issues at hand.