What is pneumonia?

Pneumonia is an inflammatory condition of the lungs caused by infection. Primarily affecting the alveoli – small air sacs deep in the lungs, where oxygen passes into the bloodstream and carbon dioxide passes out back into the lungs – pneumonia is when these air sacs become inflamed and fill with fluid.

What many people don’t realise is that pneumonia is not a specific type of infection, but rather an effect that can be created by several causes, mainly bacteria or viruses.

The severity can vary, with some patients – particularly babies, elderly people, and those with compromised immune systems or other diseases – becoming very ill. Some may need hospital treatment, and for some, it can even prove fatal.

What are the symptoms of pneumonia?

As the alveoli are filled with fluid, pneumonia can cause difficulty breathing, coughing and chest pain. Other common signs of pneumonia include:

  • Fever
  • Coughing up mucus
  • Sweating and shivering
  • Loss of appetite
  • Feeling generally unwell
  • Rapid heartbeat
  • Fatigue

Less commonly, patients may experience:

  • Headaches
  • Nausea/vomiting
  • Wheezing
  • Joint and muscle pain
  • Coughing up blood
  • Confusion/delirium – especially in older patients.

What causes pneumonia?

Many types of bacteria, viruses and even some fungi can cause pneumonia. The most common cause is infection by the bacteria Streptococcus pneumonia. Other culprits include:

  • Bacteria:
  • Haemophilus influenza
  • Straphylococcus aureus
  • Viruses
  • Respiratory syncytial virus (RSV)
  • Influenza type A
  • Influenza type B
  • Fungal pneumonia – rare in the UK
  • Aspiration pneumonia – this is caused by breathing in something harmful, such as smoke, chemicals, vomit, or a foreign object.

Those at a greater risk of catching pneumonia include babies, elderly people, smokers, people with compromised immune systems (such as those with HIV or AIDS, or people who have recently had flu), and people with other chronic health issues, such as asthma, cystic fibrosis, or heart disease.


How can it be prevented?

While most cases of pneumonia are bacterial in nature and aren’t contagious, you can reduce the risk of it spreading by maintaining good standards of hygiene, for example, by covering your mouth and nose when coughing or sneezing, throwing away tissues immediately (germs can survive for hours after leaving your body), and washing your hands regularly.

Avoiding smoking and reducing alcohol intake can help to maintain your lungs and their natural defences, as smoking and drinking can leave them weakened.

People with a higher risk of infection are advised to have the pneumococcal vaccine and flu vaccine.


What is the treatment for pneumonia?

Milder cases of pneumonia may be treated at home with plenty of rest and fluids, and by taking antibiotics (if appropriate – consult your doctor first!). For serious cases, the patient may need to be hospitalised, and treated by doctors there.

The speed of recovery depends on the individual case. It is not uncommon for recovery to take weeks, and even months for all the symptoms (particularly fatigue) to resolve.