Pneumonia

Pneumonia is an infection of the lung tissue that causes the tiny air sacs, where oxygen passes into the blood, to become inflamed and fill with fluid or pus. This makes breathing harder and can reduce the amount of oxygen reaching the body. It can affect one or both lungs and ranges from a mild illness to a serious, sometimes life-threatening condition.

Pneumonia is a common infection worldwide and a leading cause of illness in both children and adults. Anyone can develop it, but it tends to be more frequent and more serious in young children, older adults, and people with long-term health conditions or weakened immune systems. It is a significant cause of hospital admissions across all regions.

Common symptoms include a cough that may produce phlegm, fever, sweating and chills, shortness of breath, chest pain that worsens with breathing or coughing, and feeling generally unwell or tired. Some people, especially older adults, may have milder or less typical signs such as confusion. Difficulty breathing, a high fever or worsening symptoms should be assessed by a doctor.

Pneumonia is most often caused by bacteria or viruses, and sometimes by fungi. These germs reach the lungs through breathing in droplets or from infections elsewhere in the body. Risk is higher in very young children and older adults, smokers, and people with long-term lung, heart or other conditions, as well as those with weakened immune systems.

A doctor usually diagnoses pneumonia by reviewing symptoms and listening to the chest for abnormal breathing sounds. A chest X-ray can confirm the infection and show how much of the lung is affected. Blood tests, oxygen level measurements and tests on phlegm samples may be used to gauge severity and help identify the type of infection guiding the most suitable care.

Treatment depends on the cause and severity. Bacterial pneumonia is generally treated with antibiotics, while supportive care such as rest, fluids and treatments to ease symptoms helps recovery. Mild cases can often be managed at home, but more serious cases, or those in people at higher risk, may need hospital care including oxygen or fluids given directly. Follow-up ensures the infection has cleared.

The risk of pneumonia can be lowered in several ways. Vaccines are available that protect against some common causes, and staying up to date with recommended vaccinations is encouraged, especially for higher-risk groups. Not smoking, good hand hygiene, treating other infections promptly and keeping long-term conditions well managed all help protect the lungs and reduce the chance of infection.