A chest infection is an infection of the lungs or airways. The main types of chest infection are bronchitis and pneumonia.
Most bronchitis cases are caused by viruses, whereas most pneumonia cases are due to bacteria.
These infections are usually spread when an infected person coughs or sneezes. This launches tiny droplets of fluid containing the virus or bacteria into the air, where they can be breathed in by others.
The infections can also be spread to others if you cough or sneeze onto your hand, an object or a surface, and someone else shakes your hand or touches those surfaces before touching their mouth or nose.
Certain groups of people have a higher risk of developing serious chest infections, such as:
- babies and very young children
- children with developmental problems
- people who are very overweight
- elderly people
- pregnant women
- people who smoke
- people with long-term health conditions, such as asthma, heart disease, diabetes, kidney disease, cystic fibrosis or chronic obstructive pulmonary disease (COPD)
- people with a weakened immune system – this could be due to a recent illness, a transplant, high-dose steroids, chemotherapy or a health condition, such as an undiagnosed HIV infection