Overview
Pneumonia is inflammation in the lungs, usually caused by an infection. It can make the air sacs fill with fluid and cause coughing, fever, chest pain, and breathing problems. Many people recover at home, but some become seriously ill and need hospital treatment.
How common is it?
Pneumonia is common. Most people get better within a few weeks, but babies, older adults, and people with heart or lung conditions are more likely to become very unwell.
Causes and risk factors
Pneumonia can be caused by bacteria, viruses, and less often fungi. It may happen after another infection such as flu, or when food, drink, or vomit goes into the lungs by mistake.
Common risk factors
- Older age or very young age
- Smoking
- Long-term lung disease or heart disease
- Diabetes
- A weakened immune system
- Recent flu or another chest infection
- Problems swallowing or a higher risk of aspiration
Symptoms
- A cough, sometimes bringing up yellow or green mucus
- Shortness of breath
- A high temperature
- Chest pain, especially when breathing in or coughing
- Feeling very tired or achy
- Loss of appetite
- Confusion, especially in older adults
- Wheezing or grunting breathing in some children
When to see a doctor
Ask for urgent medical advice if you have chest pain, shortness of breath, a cough lasting 3 weeks or more, or cough up blood. Call 999 now if someone is struggling to breathe, has blue, pale, or blotchy lips or skin, suddenly becomes confused, or a baby is floppy or difficult to wake.
Diagnosis
A clinician will ask about symptoms, examine your chest, and may check your oxygen level. Some people need blood tests and a chest X-ray to confirm pneumonia or look for complications.
Treatments
Antibiotics or other medicines
If pneumonia is likely to be caused by bacteria, you will usually be given antibiotics. Viral pneumonia does not improve with antibiotics, but you may still need other treatment and monitoring.
Supportive care
Rest, fluids, and pain or fever relief can help while your body fights the infection. Some people also need oxygen.
Hospital treatment
If you are very unwell, are not improving, or have higher-risk health conditions, you may need fluids, antibiotics, oxygen, and monitoring in hospital.
Self-care and lifestyle
- Rest until you feel stronger and build activity back up gradually
- Drink enough fluids unless a clinician has told you to limit them
- Do not smoke while you recover
- Cover coughs and sneezes, wash your hands, and stay home if you have a fever or feel too unwell for normal activities
- Avoid cough medicines unless a clinician advises them
Prevention
Vaccines, handwashing, avoiding smoke, and treating long-term health conditions can lower the risk of pneumonia or make severe illness less likely.
Sources and review
Last reviewed: 29 July 2026 by Living Diabetes Editorial Team. This guide was checked against current patient and professional guidance. It is educational and does not replace care from your own healthcare team.