Recurrent chest infections in adults: causes, tests and when to seek help

A chest infection is an infection of the lungs or large airways. The NHS says some are mild and clear up on their own, but others can be severe and life threatening. They often follow colds or flu, and the main symptoms are a chesty cough with green or yellow mucus, wheezing and shortness of breath, chest pain or discomfort, a high temperature, headache, aching muscles and tiredness.

There is no single definition of recurrent in the general population. The NHS Lothian primary care guideline for non-cystic fibrosis bronchiectasis uses two or more chest infections annually as recurrent, and separates 2 to 3 infections in the past year from 3 or more. The NHS says that if you keep getting chest infections or are at risk of getting one, it is worth asking a GP about vaccines and other measures. In practice, if you have had several chest infections in a year, or an infection that never fully clears, it is reasonable to ask whether there is an underlying cause.

Recurrent infections are usually a sign that something is making the lungs more vulnerable or less able to clear mucus. The NHS bronchiectasis page lists several possibilities, which can overlap.

• Bronchiectasis, in which airways are damaged by inflammation, become wider than usual and produce a lot of phlegm that is hard to clear, leading to infections.

• Asthma or chronic obstructive pulmonary disease (COPD), which the NHS says commonly occur alongside bronchiectasis.

• A previous severe infection such as pneumonia, tuberculosis, measles, whooping cough or COVID-19.

• A problem with the immune system.

• Conditions such as rheumatoid arthritis or inflammatory bowel disease.

• Breathing in something that damages the lungs, such as smoke.

The NHS says that if you have symptoms of bronchiectasis a GP will listen to your chest and may arrange a sample of phlegm to check for infection, a chest X-ray, spirometry (breathing into a machine to check how well the lungs are working) and blood tests. If those suggest bronchiectasis you will be referred to a specialist for more tests such as a CT scan to confirm it, and you may need other tests to find the cause.

The NHS Lothian guideline stresses not to diagnose a chest infection based only on a positive sputum sample sent for routine microbiology. It suggests reviewing sputum pathogens and sensitivities, ensuring the right length and dose of antibiotic, advising chest physiotherapy, considering a chest X-ray particularly if there have been 3 or more infections in a year, giving smoking cessation advice, optimising any COPD or asthma treatment and considering standby antibiotics at home for suitable patients.

Treatment depends on the cause. For bronchiectasis, the NHS says it cannot usually be cured but treatment can manage symptoms and help stop them getting worse. You may see a specialist physiotherapist who teaches breathing techniques for clearing phlegm, usually done every day, and may be offered a nebuliser with salt solution, pulmonary rehabilitation, inhalers and antibiotics. You may be given antibiotics to keep at home (a rescue pack), and if you get more than 3 chest infections a year a specialist may recommend long-term antibiotics.

The NHS Lothian guideline recommends referral to secondary care for review and consideration of long-term antibiotics when infections keep happening despite the primary care measures, and states that longer antibiotic courses of up to 14 days are used in bronchiectasis because of a higher microbial load in the airways. The NHS advises exercising regularly, eating a balanced diet, washing hands regularly, avoiding people with infections such as colds and flu, having regular vaccinations such as the annual flu vaccine and the pneumococcal and COVID-19 vaccines as recommended, and not smoking.

See a GP if you have a chest infection and feel very unwell or symptoms get worse, you cough up blood or blood-stained mucus, you have had a cough for more than 3 weeks, you are pregnant, over 65, have a weak immune system or have a long-term heart, lung or kidney condition, the NHS says.

Ask for an urgent GP appointment or get help from NHS 111 if your cough is very bad or quickly gets worse, you are coughing up a few small spots or streaks of blood, you are short of breath or more breathless than usual, or you have bronchiectasis and develop a high temperature or chest pain when you breathe or cough. Call 999 or go to A&E if you cough up more than just a few spots or streaks of blood, or have severe difficulty breathing, such as gasping, choking or not being able to get words out.

The outlook depends on the underlying cause. The NHS says bronchiectasis affects everyone differently, that some people have less severe symptoms that can be managed well with treatment, and that in rare cases it can be life-threatening. Finding the cause matters because it can change treatment, for example optimising asthma or COPD care or starting airway clearance, which are among the measures the Lothian guideline lists.