Knowledge Centre
Providing rapid medical guidance and expert health insights for informational purposes. Our guides come from a Harley Street clinic, but they do not replace a professional consultation.
Chest infection: symptoms, antibiotics and recovery time
Written by Mr Stephen Lingam · Reviewed by Dr Mohammad Bakhtiar (GMC 4694470) on 25/09/2026
Key takeaways
- A chest infection is usually either acute bronchitis, which is mostly viral and settles by itself, or pneumonia, which is usually bacterial and needs antibiotics.
- Green or yellow mucus comes from white blood cells fighting infection, so its colour alone doesn't mean you need antibiotics.
- Most chest infections ease within 7 to 10 days, though a cough can hang on for three weeks or more.
- A private GP appointment at 117a Harley Street is £150, and a same-day chest X-ray can be arranged if pneumonia is suspected.
Your cold went to your chest a week ago. Now the cough is bringing up green mucus, your ribs ache from coughing, and you're wondering whether this needs antibiotics.
"Chest infection" covers two main conditions. Acute bronchitis is an infection of the large airways; it's common, usually viral, and gets better on its own. Pneumonia is an infection of the lung tissue itself; it's less common, usually bacterial, and needs antibiotics. Both cause a cough, but pneumonia makes you feel considerably worse.
If you'd like a doctor to listen to your chest today, a private GP appointment at our Harley Street clinic is £150. It includes a chest examination and an oxygen check, and if the GP suspects pneumonia, a same-day chest X-ray can be arranged at our partner imaging centre a short walk away.
Is it bronchitis or pneumonia?
The two feel different, and the difference decides the treatment. People often call either one a "lung infection"; strictly, pneumonia is the infection of the lung tissue, while bronchitis stays in the airways.
Acute bronchitis and pneumonia compared
| Acute bronchitis | Pneumonia | |
|---|---|---|
| Where | The bronchi, the main airways into the lungs | The alveoli, the tiny air sacs where oxygen passes into the blood |
| Usual cause | The viruses behind colds and flu | Bacteria, most often Streptococcus pneumoniae; sometimes viruses or fungi |
| How you feel | Persistent cough with clear, white, yellow or green mucus, sore throat, mild headache, tiredness. Usually well enough to carry on. | High temperature, often with shaking (rigors), breathlessness, sharp chest pain when breathing in, fast breathing, sometimes rust-coloured or bloody sputum |
| How long | 1 to 3 weeks; the cough can linger for up to 6 weeks | Better within about 48 hours of antibiotics; full recovery takes 2 to 6 weeks, and tiredness can last a month or more |
| Antibiotics | Not recommended by NICE for uncomplicated bronchitis | Yes, usually a 5-day course for people treated at home |
Here's the thing most people get wrong. Green or yellow mucus doesn't mean you need antibiotics. The colour comes from white blood cells fighting the infection, whether the cause is a virus or bacteria.
How long does a chest infection last?
The NHS says most chest infections get better on their own in about 7 to 10 days, although the cough and mucus can last up to three weeks. With bronchitis, the cough can linger for up to six weeks while the airways recover.
Pneumonia takes longer. Most people start to feel better within 48 hours of starting antibiotics, but full recovery takes weeks, and tiredness is usually the last thing to go.
If you've been unwell for more than three weeks and aren't improving, it's worth being examined, because a lingering cough has other causes too, from asthma to reflux.
How to get over a chest infection
Rest, plenty of fluids and paracetamol or ibuprofen for aches and fever are the mainstays. Honey in a warm drink soothes a cough for adults and older children, though honey isn't suitable for babies under 1.
Chest infections caused by viruses spread through coughs and sneezes, so cover your mouth, bin tissues straight away and wash your hands often while you're coughing.
The annual flu vaccine and the pneumococcal vaccine both reduce the risk of chest infections in vulnerable groups. Adults over 65, smokers, people with COPD, asthma, heart disease or diabetes, and anyone with a weakened immune system are more likely to develop pneumonia from what starts as simple bronchitis.
How doctors judge how serious pneumonia is
GPs use the CRB65 score to assess pneumonia. It gives one point each for new confusion, a fast breathing rate (30 breaths a minute or more), low blood pressure, and age 65 or over.
CRB65 score and what NICE advises (NG250, 2025)
| Score | Risk | Usual plan |
|---|---|---|
| 0 | Low | Treated by the GP at home, with clear advice on what to watch for |
| 1 | Intermediate | The GP decides with you: home treatment with close follow-up, or a hospital-based service |
| 2 or more | Higher | Referral to hospital for assessment |
When to be seen the same day
Book a same-day appointment, or call 0207 499 1991, if you have any of these:
- breathlessness that's getting worse
- coughing up blood
- chest pain that worsens when you breathe
- a temperature of 38°C or above that isn't responding to paracetamol
- confusion or unusual drowsiness
- symptoms getting clearly worse rather than better
If you're struggling to breathe, or your lips or fingertips look blue, call 999.
What happens at a GP appointment
A private GP appointment at 117a Harley Street costs £150 and includes a thorough chest examination, an oxygen saturation check and a clinical assessment. Same-day appointments are often available.
If pneumonia is suspected, your GP can arrange a same-day chest X-ray at our partner imaging centre nearby, along with blood tests such as CRP and a white cell count, to confirm the diagnosis and guide the choice of antibiotic.
If your symptoms fit bronchitis, your GP will explain why antibiotics won't help and what will. Not sure whether you need a doctor at all? Our guide on when to see a private GP covers the usual situations.
Mr Stephen Lingam
Managing Director
Executive leadership
Frequently asked questions
What's the difference between bronchitis and pneumonia?
Bronchitis is inflammation of the large airways, usually caused by a virus; it brings a cough, often with mucus, but most people can carry on with daily life. Pneumonia is an infection of the lung tissue itself, usually bacterial, and makes you feel much more unwell, with a high fever, breathlessness, chest pain when breathing and fatigue.
Do I need antibiotics for a chest infection?
It depends on the type. Most bronchitis is viral, so antibiotics won't help and aren't recommended, while pneumonia is usually bacterial and does need them. Your GP decides from your symptoms, the examination and sometimes a chest X-ray or blood tests.
How long does a chest infection last?
Acute bronchitis usually lasts 1 to 3 weeks, though the cough can linger for up to 6 weeks as the airways heal. Pneumonia recovery varies: many people feel better within a week of starting antibiotics, but full recovery takes 2 to 6 weeks, and tiredness often lasts longest.
Is a chest infection contagious?
The viruses that cause most chest infections spread through coughs and sneezes. Cover your mouth when you cough, bin tissues straight away and wash your hands often until the cough settles.
Is a lung infection the same as a chest infection?
People use the terms loosely. Pneumonia is an infection of the lung tissue, while bronchitis affects the airways leading into the lungs; both are commonly called chest infections.
When should I get a chest X-ray?
A chest X-ray is recommended if your GP suspects pneumonia, if your symptoms aren't improving, if you're coughing up blood, or if you have risk factors for complications such as being over 65, existing lung disease or a weakened immune system. Your GP can arrange a same-day chest X-ray at our partner imaging centre a short walk from the clinic.
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