What is pleurisy?

Pleurisy is inflammation of the thin membranes (pleura) that line the lungs and chest wall. These double-layered membranes lubricate and protect the lungs as they expand and contract inside the ribcage. If you have pleurisy, the pleural membranes become rough and rub together, causing sharp, stabbing pains in the chest.

In most cases, pleurisy occurs when a viral or bacterial infection of the airways spreads to the lining of the lungs. Less commonly, pleurisy may be caused by another medical condition or lung problem.

Pleurisy is also sometimes referred to as pleuritis or pleuritic chest pain.

The pleura

The lungs are surrounded by a thin membrane, known as the visceral pleura. A second, outer membrane, known as the parietal pleura, lines the inside of the chest cavity and attaches to the ribcage. The narrow pleural space between the two membranes contains about four teaspoons of fluid. This fluid allows the two layers to glide smoothly across one another as the lungs expand and contract during breathing.

Causes

Pleurisy occurs when the pleural membranes become inflamed, usually due to an infection of the airways with viruses or bacteria. During inflammation, the surfaces become rough and the fluid can get sticky. This causes the two membranes to rub together, causing pain in the chest.

A healthy lung compared to a red, inflamed and swollen lung affected by pleurisy.Pleurisy causes inflammation and swelling of the pleural membranes that surround the lungs. 

Infection

Any type of infection can lead to pleurisy, but the most common cause is a virus that spreads from the airway to the lining of the lungs. Viruses known to cause pleurisy include cytomegalovirus, Epstein-Barr virus and those that also cause influenza and parainfluenza. Less commonly, pleurisy may be caused by a bacterial infection, such as the type that causes pneumonia or tuberculosis.

Viruses and bacteria irritate the pleural membranes in the same way they irritate the lining of the nose and airways during a common cold.

Other causes

Any other factor that results in damage and inflammation to the lung surface or pleural membranes can cause pleurisy. Some examples include a chest injury, blood clot in a lung (pulmonary embolism), collapsed lung (pneumothorax) or lung cancer.

Certain conditions that cause inflammation may also affect the linings of the lungs. For example rheumatoid arthritis, inflammatory bowel disease or lupus can lead to pleurisy.

In most cases, pleurisy related to an underlying lung problem or medical condition will have an additional set of symptoms related to the cause.

Cytomegalovirus

A common herpes-type virus that usually only causes a mild flu-like illness in healthy people, but that can cause a range of illnesses in people with compromised immune systems or babies of women who are infected while pregnant.

Epstein-Barr virus

A virus of the herpes family that causes mononucleosis, also known as mono or glandular fever. It is also implicated in some other medical conditions.

Inflammatory bowel disease

A group of conditions characterised by chronic, episodic inflammation of the bowels, including Crohn's disease and ulcerative colitis.

Parainfluenza

An illness caused by viruses similar to influenza viruses. Can cause respiratory infections, particularly in children.

Pulmonary embolism

A blockage of an artery in the lungs usually by a blood clot, but can be by a fat globule, air bubble or another substance that has travelled from elsewhere in the body.

Pneumothorax

A medical condition where air escapes out of the lungs and into the chest cavity. It causes all or part of a lung to collapse. Also known as a collapsed lung.

Risk factors

The chances of developing pleurisy are increased by one or more of the following factors:

  • Being prone to viral or bacterial infections;
  • Exposure to asbestos;
  • A chest injury, such as a rib fracture, and;
  • An underlying lung condition.

Types

Pleurisy can be described as 'wet' or 'dry', depending on whether a build-up of fluid occurs in the pleural space between the two pleural membranes.

Wet pleurisy

In wet pleurisy, an abnormal volume of fluid collects in the pleural space. Sometimes the fluid is produced as part of the body's natural immune response to infection, or it may be due to poor drainage. The medical term for this build-up of fluid is pleural effusion.

Although a large amount of fluid can reduce pain by preventing the pleural membrane from rubbing together, the related increase in pressure can lead to complications, such as a collapsed lung or infection.

A build-up of fluid in the pleural space, also known as pleural effusion.Pleural effusion is the build-up of fluid that occurs in 'wet' pleurisy. 

Dry pleurisy

As the name suggests, dry pleurisy describes inflammation of the lung lining without abnormal fluid production. Sometimes, dry pleurisy can develop into wet pleurisy over time.

Pleural effusion

An abnormal build-up of fluid in the space between the lungs and the inside wall of the chest.

Signs and symptoms

The most common symptom of pleurisy is a moderate to severe stabbing pain in the chest that feels worse during breathing, coughing or sneezing. Sometimes, the pain may also be felt in the neck, back or shoulder. It may be continuous, or it may come and go.

Other symptoms of pleurisy include:

  • Fever and chills;
  • An ongoing dry cough;
  • Fast, shallow breathing, and;
  • Shortness of breath.

Symptoms of pleurisy usually last between a few days to about two weeks.

Methods for diagnosis

A diagnosis of pleurisy is usually based upon symptoms and characteristic findings from listening to the chest with a stethoscope. Your doctor may also collect a blood sample or look more closely at your chest and lungs using an X-ray, ultrasound or computerised tomography (CT) scan.

Computerised tomography

A scan that uses X-rays to create a 3D image of the body. This can detect abnormalities more effectively than a simple X-ray can.

Ultrasound

A scan that uses high-frequency soundwaves to produce images of the body’s internal structures.

X-ray

A scan that uses ionising radiation beams to create an image of the body’s internal structures.

Types of treatment

Treatments for pleurisy will depend on the underlying cause.

For example, pleurisy caused by a viral infection usually clears up after a few days without the need for prescription medication. However, your doctor may recommend rest and an over-the-counter medication, such as paracetamol or ibuprofen, to help control the pain.

In contrast, you may be prescribed an antibiotic medication if your pleurisy is caused by a bacterial infection.

Potential complications

Potential complications of pleurisy include:

  • Breathing difficulties;
  • Build-up of fluid around the lungs (pleural effusion);
  • A collapsed lung (pneumothorax), and;
  • Infection of fluid in the pleural space.

Pleural effusion

An abnormal build-up of fluid in the space between the lungs and the inside wall of the chest.

Pneumothorax

A medical condition where air escapes out of the lungs and into the chest cavity. It causes all or part of a lung to collapse. Also known as a collapsed lung.

Prognosis

The outlook for pleurisy differs from person to person, depending on the cause. Pleurisy caused by a viral infection usually clears on its own in a few days without any particular treatment, while pleurisy caused by a bacterial infection can also be successfully treated in most cases, but complications and lasting lung damage are more likely.

Prevention

Although pleurisy is not technically contagious, the viruses and bacteria that cause it may be spread by coughing, sneezing and having close contact with infected people. For this reason, it may be possible in some cases to prevent pleurisy by avoiding people who are unwell and staying away from organised activities if you have an infection. Similarly, practicing good hygiene habits may help to prevent the spread of viruses and bacteria.

Vaccinations against Streptococcus pneumonia (pneumococcal bacteria), Haemophilus influenzae type B (Hib) and the seasonal flu virus may also help to prevent the infections that could lead to pleurisy.