A chest infection is an infection that affects your lower large airways (bronchi) and your lungs. Pneumonia and bronchitis are the most common chest infections. Bronchitis is usually caused by a viral infection. Pneumonia is usually due to bacterial infection. Pneumonia may be serious and need hospital admission.
None of us like colds - and none of us can avoid them unless we plan to live our lives in a sterile bubble. But even though they can't be 'cured', at least they settle with no ill effects within a few days. Chest infections, on the other hand, can range from mild but unpleasant to life-threatening - and catching them early is key to reducing the risk of serious complications. That's why it's essential to know how to spot the signs of a chest infection.
What is a chest infection and what causes it?
Your 'respiratory tract' runs from your nose all the way down to the alveoli - tiny air spaces deep inside your lungs. Doctors call the large airways (bronchi) of the lungs and the lungs themselves the lower respiratory tract. A chest infection is an infection affecting your lower respiratory tract. Any infection higher up (including your nose and throat) is known as an upper respiratory tract infection (URTI).
The vast majority of URTIs are caused by viral infections. Your immune system will fight these off without any help within a few days. Because URTIs are caused by viruses rather than bacteria, antibiotics won't help in any way.
Read more about antibiotics to treat respiratory tract infections.
Sometimes an infection in the upper airways can spread deeper, causing a chest infection. Sometimes germs (bacteria) already living in your lungs can multiply, with the same result.
There are two main types of chest infection - acute bronchitis and pneumonia.
- Acute bronchitis - Bronchitis is inflammation due to infection of the bronchi. '-itis' is the medical term for inflammation. It can be acute or chronic. Acute means lasting a short time and chronic means lasting a long time. Acute bronchitis is common and is often due to a viral infection. Infection with a germ (bacterium) is a less common cause. See separate leaflet called Acute Bronchitis for more details.
- Pneumonia - This is usually a bacterial infection of the lung and may be serious. Treatment with antibiotics is usually needed. See separate leaflet called Pneumonia for more details.
Who gets chest infections?
- Young children and the elderly.
- People who smoke.
- Pregnant women.
- People with long-term chest problems such as asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis, heart disease, diabetes, kidney disease or liver disease.
- People with an immune system that's weakened either by conditions such as some cancers (including lymphoma, myeloma and leukaemia) or AIDS; or by treatments such as high-dose steroids, chemotherapy or other medicines that can suppress your immune system.
What are the symptoms of a chest infection?
A cold - often called an upper respiratory tract infection (URTI) - usually starts with a combination of blocked and/or runny nose and sneezing, sometimes with a mild high temperature (fever). You will usually get a cough, which is often dry and harsh but can also sound like you have a lot of phlegm (sputum), which you may bring up. You may also feel tired and achy, but these symptoms are usually fairly mild and you'll be able to keep going with everyday activities. Chest infections can start with these symptoms too, but you don't need to see a doctor if these are the only symptoms you have. The only exceptions are people with long-term lung conditions like chronic obstructive pulmonary disease (COPD) who are more likely to develop serious complications.
The main symptoms of a chest infection are:
- A chesty cough.
- Breathing difficulties (including shortness of breath and wheezing).
- Chest pain or tightness.
- High temperature.
- Muscle aches and pains.
- Feeling very tired.
- A rapid heartbeat.
When should you see a doctor?
Infection of the large airways (bronchi) in the lungs (acute bronchitis) usually gets be