A chest infection is an infection of the airways leading down to the lungs, or an infection in the lungs themselves. 'Chest infection' is a general term that covers a number of conditions, including pneumonia and bronchitis.
People with a chest infection almost always have a cough, which may bring up phlegm (thick mucus) from their chest. The common cold is also caused by an infection that causes a cough, but as the infection is limited to the nose and throat, it is much less likely to cause any significant problems.
In the UK, acute bronchitis affects about 4.5% of the population each year. The condition is most common during the autumn and winter months.
A rarer form of chest infection is pneumonia, which affects between 0.05-1.1% of people. Most people who have the condition have mild pneumonia but it can potentially be very serious, so it is important to seek immediate treatment.
The two main types of chest infection – acute bronchitis and pneumonia are described below.
Acute bronchitis is an infection of the lining of the air tubes of the lungs, which are known as the bronchi. The infection is normally caused by a virus. It often follows a cold or the flu. Smoking increases your chances of getting the infection. Most people do not require medical treatment as the infection normally passes within 7-10 days.
Pneumonia is an infection that causes tiny air sacs in your lungs to become inflamed and filled with fluid. It is sometimes known as 'community-acquired pneumonia' because people often catch it during the course of their daily lives, such as at work or at school.
Pneumonia is usually caused by bacteria, although some cases of pneumonia can also be caused by viruses. People with mild pneumonia can usually be treated at home. However, if you have severe pneumonia, you may need to receive treatment in hospital. Those who are very young, very old, and those with another serious health condition, are more likely to require hospital treatment.
The risk of spreading bacteria to other people can be reduced by covering your mouth when you cough or sneeze, and by washing your hands regularly. You should also throw away used tissues immediate.
The symptoms of acute bronchitis and pneumonia can be similar - for example, a cough that brings up phlegm (thick mucus), and a high temperature. However, the key difference between the symptoms of acute bronchitis and pneumonia is that pneumonia is more severe.
When should I seek medical help for someone with a cough?
It is difficult to distinguish between a cough that is caused by a simple cold, acute bronchitis and pneumonia, from symptoms alone. Seek medical help if a person with a cough develops any of following problems:
- They feel, or look, significantly unwell and they are not managing well with daily activities,
- they are confused or disorientated,
- they have a temperature above 38C (100F),
- they have a high resting pulse rate (compared to normal),
- they are breathless at rest, or become breathless more easily than they would normally expect with exertion,
- they have a sharp pain in their chest when they breathe in (pleuritic pain),
- they cough up blood stained phlegm (thick mucus),
- they have a cough that last longer than three weeks,
- they have a significant long term health problem, such as diabetes, heart failure or any other long term condition that causes breathlessness,