This information is for people with pneumonia, their families, friends and carers.

This section tells you the basic facts about pneumonia, how it is caused, the symptoms to look out for, and how it can be treated. You can also read advice to help prevent pneumonia.

What is pneumonia?

Pneumonia is an inflammation of one or both lungs, which is usually caused by an infection. This inflammation causes the tiny air sacs (called the alveoli) inside your lungs to fill with fluid. This makes it harder for the lungs to work properly. Your body sends white blood cells to your lungs to try to fight the infection. Although this helps kill the germs, it can also make it harder for your lungs to pass oxygen into your bloodstream.

lungs for IPF

What causes pneumonia?

Many different kinds of bacteria, viruses and, occasionally, fungi can cause pneumonia. The most common cause is a type of bacteria called Streptococcus pneumoniae, but in individual cases the cause can be unknown.

In winter the number of cases of pneumonia rises. This is because of infection spreading from person to person, and also because other infections are more common in the winter, such as influenza (flu). An infection with flu can lower your immune system, increasing your risk of picking up pneumonia.

What are the symptoms?

If you have pneumonia, you will feel unwell and experience symptoms that are similar to flu or a chest infection. The symptoms usually develop gradually over days, but sometimes they can progress much faster.

Almost all people with pneumonia will have a high temperature. This can sometimes be very high and you might also sweat and shiver. Another symptom is a cough that brings up phlegm (mucus).

If your breathing is quick, this suggests that the pneumonia is likely to be severe. Confusion is also a serious sign. 

A sharp pain in the side of your chest, which becomes worse when you take a deep breath, usually means that pleurisy has developed. This happens when the thin outer covering of the lung becomes infected and inflamed by the pneumonia.

If you are experiencing the symptoms described on this page, seek medical advice as soon as possible.

Who is most at risk?

Anyone of any age can get pneumonia. In adults, approximately 5-11 people out of every 1,000 get pneumonia each year in the UK. Pneumonia can be more of a threat for two groups of people:

  • First, there are people who have a higher risk of developing pneumonia, such as those with a weaker immune system.
  • Second, there are people who are not at extra risk of developing pneumonia, but if they do develop it they may experience worse effects. This group includes people with heart or lung disease and other medical conditions.

Both these groups need to take more care to reduce their chances of developing pneumonia and any potential complications.  People in these high-risk groups include:

  • babies and infants
  • older people
  • people with long-term heart, lung and kidney diseases, and those with diabetes
  • people with cancer, especially those having chemotherapy or who have leukaemia or lymphoma
  • people who smoke or drink alcohol to excess
  • people receiving drugs that suppress the immune system, and those with HIV/AIDS

In addition to these groups, people who are in hospital for other problems sometimes develop pneumonia while they are there. This does not mean that the hospital is unhygienic, but that their resistance to the germs that can cause pneumonia has been weakened by their other medical problems.

Preventing pneumonia

Not smoking is essential to reduce the risk of pneumonia. Smokers have an increased risk of developing pneumonia as well as other chest infections – and so do children whose parents smoke.

The viral infections that are common in winter can increase the risk of pneumonia. Therefore, it’s important to practise good hygiene to reduce the spread of germs, and to use a tissue when you cough or sneeze and dispose of it immediately.

There are two types of vaccine available for pneumonia, but they only protect against the most serious cases caused by the commonest bacteria, which is called Streptococcus pneumoniae. They are aimed at protecting anyone for whom pneumonia is likely to be more common or serious, including young babies and older people.

The pneumococcal conjugate vaccine (PCV) is provided to infants by the NHS, with the first dose given at two months old.

The second type of vaccine, pneumococcal polysaccharide vaccine (PPV), is available for adults over the age of 65 and anyone over the age of two who fall into a high-risk category. Most adults will only need to have it once.

It is also a good idea for those who are at risk of developing pneumonia to have the flu vaccine, as flu can sometimes lead to pneumonia. This vaccination has to be given each winter and is available at many high street chemists. Some people are eligible to receive the vaccine for free.

To find out more about vaccinations for pneumonia or flu, talk to your GP or call the BLF Helpline.

Diagnosis and treatment

A doctor can often diagnose pneumonia based on the symptoms described in this leaflet and by examining your chest, but you may need to have a chest X-ray to confirm that you have it.

The main treatment for pneumonia is antibiotics, along with rest and drinking plenty of water. Some people with mild pneumonia can manage the condition at home with treatment from their GP, especially if they are otherwise fit and well and have support from family and friends. However, some people will need to go to hospital, where both antibiotics and fluids may be given by drip into a vein and oxygen can be provided. If you are very ill and need help with breathing, you may be put on a ventilator – a machine that moves air in and out of your lungs if you are unable to breathe normally.

People who have been admitted to hospital with other medical problems and then develop pneumonia have a high risk of becoming very ill and may need different, more powerful antibiotics.


If you have milder pneumonia, this will usually mean a few days or a week of being unwell, followed by a steady return to normal activity. Severe pneumonia, which needs hospital admission, might mean it takes weeks or months to feel fully fit again.

The vast majority of people will recover from pneumonia and return to good health. However, some people with severe pneumonia don’t survive despite the best available care. The most recent statistics show that between 5 and 14 per cent of people who are admitted to hospital with pneumonia sadly die.

Next steps:

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Last medically reviewed: November 2013. Due for review: November 2016.

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