Pneumonia is swelling (inflammation) of the tissue in one or both lungs. It's usually caused by a bacterial infection.

At the end of the breathing tubes in your lungsare clusters of tiny air sacs. If you have pneumonia, these tiny sacs become inflamed and fill up with fluid.

Symptoms of pneumonia

The symptoms of pneumoniacan develop suddenly over 24 to 48 hours, or they may come on more slowly over several days.

Commonsymptomsof pneumoniainclude:

  • a Cough which may be dry, or produce thick yellow, green, brown or blood-stainedmucus (phlegm)
  • difficulty breathing your breathing may be rapid and shallow, and you may feel breathless, even whenresting
  • rapid heartbeat
  • fever
  • feeling generally unwell
  • sweating and shivering
  • loss of appetite
  • chest pain which gets worse when breathing or coughing

Less common symptoms include:

  • coughing up blood (haemoptysis)
  • headaches
  • fatigue
  • nausea or vomiting
  • wheezing
  • joint and muscle pain
  • feeling confused and disorientated, particularly in elderly people

When to see your GP

See your GP if youfeel unwell and you have typical symptoms of pneumonia.

Seek urgent medical attention if you're experiencing severe symptoms, such asrapid breathing,chest painor confusion.

Who's affected?

In the UK, pneumonia affects around8in 1,000 adults each year. It's more widespreadin autumn and winter.

Pneumonia can affect people of any age, but it's more common and can be more seriousin certain groups of people, such as the very young or the elderly.

People in these groups are more likely to need hospital treatment if they develop pneumonia.

What causes pneumonia?

Pneumonia is usually the result ofa pneumococcal infection , caused by bacteria calledStreptococcus pneumoniae.

Many different types of bacteria, includingHaemophilus influenzae and Staphylococcus aureus, can also cause pneumonia, as well as viruses and, more rarely, fungi.

As well as bacterial pneumonia, other types include:

  • viral pneumonia most commonly caused by the respiratory syncytial virus (RSV) and sometimes influenza type A or B; viruses are a common cause of pneumonia in young children
  • aspiration pneumonia caused by breathing in vomit,a foreign object, such as a peanut,or a harmful substance, such as smoke or a chemical
  • fungal pneumonia rare in the UK and more likely to affect people with a weakened immune system
  • hospital-acquired pneumonia pneumonia that develops in hospital while being treated for another condition or having an operation; people in intensive care on breathing machines are particularly at risk of developing ventilator-associated pneumonia

Risk groups

The following groups have an increased risk of developing pneumonia:

  • babies and very young children
  • elderly people
  • people who smoke
  • people with other health conditions, such as asthma , cystic fibrosis , or a heart, kidney or liver condition
  • people with a weakened immune system for example, as a result of a recent illness, such as flu , having HIV or AIDS , having chemotherapy ,or taking medication following an organ transplant

Diagnosing pneumonia

Your GP may be able to diagnose pneumonia by asking about your symptoms and examining your chest. Further tests may be needed in some cases.

Pneumonia can be difficult to diagnose because it shares many symptoms with other conditions, such as the common cold , bronchitis and asthma .

To help make a diagnosis, your GP may ask you:

  • whetheryou feel breathless or you're breathing faster than usual
  • how long you've had your cough,and whether you're coughing up mucus and what colour it is
  • if the pain in your chest is worse when you breathe in or out

Your GP may also take your temperature and listen to your chest and back with a stethoscope to check for any crackling or rattling sounds.

They may also listen to your chest by tapping it. Lungs filled with fluid produce a different soundfrom normal healthy lungs.

If you have mild pneumonia, you probably won'tneed to have a chest X-ray or any other tests.

You may need a chestX-ray or other tests, such as a sputum (mucus) test or blood tests ,if your symptoms haven't improved within 48 hours of starting treatment.

Treating pneumonia

Mild pneumonia can usually be treated at home by:

  • getting plenty of rest
  • taking antibiotics
  • drinking plenty of fluids

If you don't have any other health problems, you should respond well to treatment and soon recover, although your cough may last for some time.

As pneumonia isn't usually passed from one person to another, it's safe to be around others, including family members.

However, people with a weakened immune system should avoid close contact with a person with pneumonia until they start to get better.

For at-risk groups, pneumonia can be severe and may need to be treated in hospital.

This is because it can lead to serious complications, which in some cases can be fatal, depending on a person's health and age.

Preventing pneumonia

Although most cases of pneumonia are bacterial and aren't passed on from one person to another, ensuring good standards of hygiene will help prevent germs spreading.

For example, you should:

  • cover your mouth and nose with a handkerchief or tissue when you cough or sneeze
  • throw away used tissues immediately germs can live for several hours after they leave your nose or mouth
  • wash your hands regularly to avoid transferring germs to other people or objects

A healthylifestyle can also help prevent pneumonia. For example, you should avoid smokingas it damages your lungs and increases the chance of infection.

Find outhow to stop smoking .

Excessive and prolonged alcohol misuse also weakens your lungs' natural defences against infections, making you more vulnerable to pneumonia.

People at high risk of pneumoniashould be offered the pneumococcal vaccine and flu vaccine .

Content supplied by the NHS Website

Medically Reviewed by a doctor on 4 Jan 2017