What causes pleurisy? 

Pleurisy is an inflammatory condition that affects the pleura, the double  layered membrane surrounding the lungs. It is rarely a standalone illness and is almost always a secondary symptom of an underlying medical issue. Identifying the root cause is the primary goal of clinical management, as the treatment varies significantly depending on whether the inflammation is triggered by an infection, a physical injury, or a chronic health condition. 

What We Will Cover in This Article 

• The most common infectious causes, including viruses and bacteria 

• How physical chest injuries can lead to pleural inflammation 

• The role of autoimmune conditions in chronic pleurisy 

• Rarer but serious causes such as pulmonary embolism 

• Environmental and lifestyle factors that impact the pleura 

• Emergency guidance for sudden or severe chest discomfort 

Infectious causes of pleurisy 

The most frequent cause of pleurisy in the UK is a viral infection, such as the flu ‘influenza’ or the common cold. These viruses can cause the pleural layers to swell and rub together, creating sharp pain. Bacterial infections, particularly pneumonia, are also major causes. When an infection in the lung tissue spreads to the surface, it irritates the pleural lining, leading to a condition known as pleuritis. 

In some cases, a bacterial infection can cause a buildup of pus in the pleural space, a serious complication known as an empyema. This requires intensive clinical treatment, often involving a chest drain to remove the infected fluid. 

Infection Type	Specific Examples	Likelihood of Pleurisy
Viral	Influenza, RSV, Parainfluenza	Very common; often resolves with the virus
Bacterial	Pneumonia, Tuberculosis	Common; often involves fluid buildup
Fungal	Aspergillosis, Histoplasmosis	Rare; usually in immunocompromised patients
Parasitic	Amoebiasis	Extremely rare in the UK

Physical trauma and lung conditions 

Non  infectious causes of pleurisy often involve direct physical impact or underlying diseases that affect the chest cavity. A fractured or severely bruised rib can cause the pleura to become inflamed in the localized area of the injury. Similarly, certain conditions that affect the blood vessels or tissues of the lungs can manifest as pleural pain. 

A pulmonary embolism ‘a blood clot in the lung’ is a critical cause of pleurisy that requires immediate emergency care. The clot blocks blood flow to a portion of the lung, causing the overlying pleura to become inflamed and painful. 

• Rib Fractures: Sharp bone edges or impact can irritate the lung lining. 

• Lung Infarction: Death of a small area of lung tissue due to a clot. 

• Pneumothorax: A collapsed lung that allows air to enter the pleural space. 

• Asbestosis: Long term exposure to asbestos fibres can scar and inflame the pleura. 

Autoimmune and systemic causes 

In some individuals, pleurisy is caused by the body’s own immune system attacking the pleural tissue. This is seen in chronic autoimmune conditions such as Rheumatoid Arthritis or Systemic Lupus Erythematosus ‘Lupus’. In these cases, the pleurisy may be chronic or recurring, rather than a one  off event tied to an infection. 

Autoimmune Condition	How it Affects the Pleura	Clinical Sign
Lupus ‘SLE’	Generalised inflammation of serous membranes	Recurring pleuritic chest pain
Rheumatoid Arthritis	Development of small nodules on the pleura	Pleural effusion ‘fluid buildup’
Sarcoidosis	Growth of tiny inflammatory cells ‘granulomas’	Shortness of breath and dry cough

To Summarise 

The causes of pleurisy are diverse, ranging from common viral infections and pneumonia to physical injuries and autoimmune diseases. Because it is a symptom of another problem, clinicians must diagnose the underlying trigger to provide the correct treatment. Whether caused by a simple virus or a serious blood clot, the resulting inflammation of the lung lining is a painful condition that warrants medical evaluation to ensure patient safety. 

If you experience sudden, sharp chest pain accompanied by difficulty breathing, coughing up blood, or feeling faint, call 999 immediately. 

Authority Snapshot 

The clinical information regarding the causes of pleurisy is derived from the diagnostic standards of the NHS and the British Thoracic Society. These guidelines ensure that clinicians investigate the full range of potential triggers, from minor infections to life  threatening embolisms. This article has been written to provide a safe, clear, and medically accurate overview of how pleurisy develops and is reviewed by medical professionals for accuracy. 

Dr. Stefan Petrov is a UK  trained physician with an MBBS and postgraduate certifications including Basic Life Support ‘BLS’, Advanced Cardiac Life Support ‘ACLS’, and the UK Medical Licensing Assessment ‘PLAB 1 & 2’. He has hands  on experience in general medicine, surgery, anaesthesia, ophthalmology, and emergency care. Dr. Petrov has worked in both hospital wards and intensive care units, performing diagnostic and therapeutic procedures, and has contributed to medical education by creating patient  focused health content and teaching clinical skills to junior doctors.