Recurrent chest infections

What can cause repeated chest infections?

Common and important causes include:

• Bronchiectasis – widened, damaged airways where mucus collects
• Asthma or COPD – flare-ups are often mistaken for infection, and inflammation can make infection more likely
• Allergic bronchopulmonary aspergillosis (ABPA) – an allergic reaction to a common mould
• Weakened immunity, including low antibody levels, which can be tested and treated
• Swallowing problems or reflux, where small amounts of food or stomach contents enter the airways
• Non-tuberculous mycobacteria (NTM) and other less common infections
• Less often, a blockage in an airway, rheumatoid arthritis, inflammatory bowel disease, primary ciliary dyskinesia or alpha-1 antitrypsin deficiency

How we investigate

Your consultant asks about the number of infections, sputum, previous antibiotic courses, smoking, swallowing, reflux, nasal symptoms and other conditions. Tests are chosen for you and may include:

• a high-resolution CT scan of the chest – the key test for bronchiectasis
• sputum samples for bacteria, fungi and mycobacteria
• blood tests, including a full blood count, immunoglobulins and vaccine antibody responses, total IgE and Aspergillus tests, and alpha-1 antitrypsin
• spirometry or full lung function tests
• sometimes a bronchoscopy to obtain samples or look for a blockage

Bronchiectasis

Bronchiectasis is a long-term condition in which damaged airways become abnormally widened. Mucus collects, increasing the risk of infection. It can follow infections or occur with immune and other conditions; sometimes no cause is found. Common symptoms are a persistent cough, sputum, repeated infections, breathlessness and tiredness. Some people cough up blood.

Personalised airway-clearance techniques, ideally taught by an experienced respiratory physiotherapist, are central to care. Physical activity and pulmonary rehabilitation can improve exercise capacity and symptoms. Flare-ups are treated promptly with antibiotics, usually for 14 days, guided by sputum results. People who have frequent flare-ups may benefit from long-term preventive treatment, such as a macrolide antibiotic (for example azithromycin) or inhaled antibiotics, with safety checks and monitoring. Inhaled steroids are not routinely used for bronchiectasis alone.

Allergic bronchopulmonary aspergillosis (ABPA)

ABPA is an allergic reaction to Aspergillus fumigatus, a mould found widely in the environment. It usually occurs in people with asthma and can cause poorly controlled asthma, repeated flare-ups, coughing up brown plugs of mucus and, over time, bronchiectasis.

Diagnosis combines blood tests – a raised total IgE, Aspergillus-specific IgE and IgG, and eosinophils – with a CT scan. Treatment aims to settle the allergic inflammation and prevent lung damage, usually with steroid tablets and/or an antifungal medicine such as itraconazole, with monitoring of IgE levels and side effects. Biologic treatments are sometimes used in selected patients.

Pseudomonas aeruginosa

Pseudomonas aeruginosa is a bacterium that can infect damaged airways, particularly in bronchiectasis and advanced COPD. Long-term infection is linked with more flare-ups and a faster decline in lung health, so it is treated actively.

When Pseudomonas is first found, a course of eradication treatment is usually offered, often an antibiotic tablet followed by an inhaled antibiotic, sometimes with intravenous antibiotics. If infection persists, long-term inhaled antibiotics can reduce flare-ups. Regular sputum samples guide treatment, as Pseudomonas can become resistant to some antibiotics.

Reducing future infections

• Keep up airway clearance every day if it has been recommended.
• Have recommended vaccinations, including flu, pneumococcal and COVID-19 vaccines, and RSV vaccination if you are eligible.
• Agree a self-management plan, including when to send a sputum sample and start rescue antibiotics.
• Stop smoking, with support from NHS Stop Smoking Services.

Cystic fibrosis

We do not provide assessment or treatment for cystic fibrosis (CF). If you have, or may have, CF, your care should be led by a specialist adult CF centre. In London, the adult CF service at the Royal Brompton Hospital is a leading centre; your GP can refer you.

Sources and further information

• BTS guideline for bronchiectasis in adults
• ERS 2025 bronchiectasis guideline: European Lung Foundation patient guide
• NHS: bronchiectasis
• NHS: aspergillosis
• National Aspergillosis Centre patient support
• Cystic Fibrosis Trust: adult specialist CF centres

This guide gives general information for adults and does not replace individual medical advice.