Acute bronchitis and chesty cough explained

What acute bronchitis is

Acute bronchitis is inflammation of the main airways in the lungs, the bronchi, usually following a cold or flu. When these airways become irritated and swollen, they produce extra mucus, and the body coughs to clear it. This gives the classic chesty cough, which may bring up clear, yellow, or greenish phlegm; the colour does not reliably tell you whether antibiotics are needed. Other symptoms can include a sore throat, a blocked or runny nose, tiredness, wheezing, and a mild fever. Acute bronchitis is different from pneumonia, which is a deeper infection of the lung tissue, and from long-term (chronic) bronchitis, which is part of COPD and linked with smoking. In most otherwise healthy people, acute bronchitis is short-lived and not serious.

Why it happens and how it spreads

The great majority of acute bronchitis is caused by viruses, the same kinds that cause colds and flu, rather than bacteria. This is one of the main reasons antibiotics are usually unhelpful. The infection spreads like a cold, through droplets when someone coughs or sneezes, and by touching surfaces then the face. Smoking, breathing in fumes or dust, and having other lung conditions such as asthma can make the airways more sensitive and the cough more troublesome. After the infection has cleared, the cough can linger for a couple of weeks because the airways stay irritated for a while, which is normal and does not mean the infection is getting worse. Good hand hygiene and staying away from others when unwell reduce spread.

How long it lasts and self-care

A cough from acute bronchitis often lasts around three weeks, sometimes longer, even after other symptoms have gone. Because it is usually viral, the aim of self-care is to stay comfortable while the body recovers. Rest, drink plenty of fluids, and stop smoking if you can, as smoke irritates the airways. Simple over-the-counter pain relief taken as directed can ease a sore throat, aches, or fever. Warm honey and lemon drinks can soothe a cough for adults and children over one year, though honey is not for babies under one. There is little strong evidence that cough medicines work, but a pharmacist can advise if you want to try something. A community pharmacist is a good first port of call for advice and reassurance.

Why antibiotics usually are not needed

Because acute bronchitis is nearly always viral, antibiotics, which only work against bacteria, generally make little or no difference to how quickly you recover. NICE guidance recommends against routinely offering antibiotics for acute bronchitis in otherwise healthy people, because the small possible benefit is outweighed by side effects and by the wider problem of antibiotic resistance. Antibiotics may be considered for people who are systemically very unwell, or who are at higher risk of complications, such as those with significant heart or lung disease or a weakened immune system. A clinician weighs these factors individually. For most people, the best approach is self-care and patience, using a pharmacist for advice and knowing which symptoms should prompt a review.

When to seek medical help

See a GP or call NHS 111 if a cough lasts more than about three weeks, if you keep getting chest infections, if you cough up blood, or if you feel very unwell, breathless, or have a high fever that does not settle. People with asthma, COPD, heart disease, or a weakened immune system should seek advice sooner, as they are more prone to complications. Phone 999 or go to A&E for severe breathing difficulty, chest pain, blue-tinged lips or face, or new confusion, as these can signal a more serious problem such as pneumonia. Getting an urgent review also matters if a young child, older person, or frail relative becomes rapidly worse. Trust your instincts: if something feels seriously wrong, seek help promptly.