Pneumonia symptoms, causes and risk factors

Pneumonia is an inflammation of the lung tissue affecting one or both sides of the chest that often occurs as a result of an infection.

Pneumonia is an infection in one or both lungs usually caused by bacteria, viruses, or fungi
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Concerned about pneumonia? Pneumonia is an infection in one or both lungs usually caused by bacteria, viruses, or fungi. We look at who's at risk of pneumonia, the symptoms to look out for and how it is treated:

What is pneumonia?

Pneumonia is an inflammation of the lung tissue affecting one or both sides of the chest, that often occurs as a result of an infection. It is still a common disease affecting around one per cent of the adult UK population each year.

Many people die from pneumonia every year, most commonly women and especially people over the age of 70. The overall death rate due to pneumonia is currently 5 per cent, ie around 1 in 20 people contracting the condition die from it.

Pneumonia causes

Pneumonia has a number of potential causes, including infection, toxic inhalation and allergic reaction:

• Pneumonia and infection

Pneumonia infection can be caused by a lot of different micro-organisms including viruses, fungi (eg histoplasmosis), parasites and half of all pneumonia cases are caused by bacteria. The bacteria, known as streptococcus pneumoniae is the main cause of the most typical pneumonia.

• Pneumonia and toxic inhalation

In addition to infection, pneumonia can also be caused by corrosive chemicals breathed into the lungs or toxic smoke inhalation from a fire.

• Pneumonia and allergic reaction

Rarely, pneumonia can result from you breathing in something that you are allergic to. This may be related to a hobby or to your employment. The medical term for pneumonia caused by an allergy is extrinsic allergic alveolitis. An example of this condition is farmer's lung, caused by breathing in the dust from mouldy hay.



Pneumonia symptoms

Pneumonia symptoms can develop suddenly or may come on slowly over several days, and may include the following:

✔️ Classic bacterial pneumonia starts suddenly with shivering fits, fever, pains in the chest and coughing.

✔️ The cough is dry at first, but in a day or two the person starts to cough up phlegm. The phlegm is usually yellow, blood-stained or rust-coloured.

✔️ Breathing is typically fast and shallow. The infected person may gasp for air and may even go bluish around the lips and nails due to the lack of air (cyanosis).

✔️ It hurts to breathe in deeply or cough. This may be a sign that the inflammation has spread to the membrane that covers the lungs (pleurisy).

✔️ The patient may be in an acute confusional state, more common in the elderly.

✔️ There may also be a serious outbreak of herpes (cold sores) around the mouth, which shows that your immune system is not now able to defend against the herpes virus.

If you catch a cold, that doesn't seem to go away, or recognise the symptoms mentioned above, it is important to seek medical advice.



Who is at risk of pneumonia?

Pneumonia can affect anyone of any age, but certain groups are more at risk including the following:

• Children

Children are at higher risk of pneumonia, especially when chronically ill. Childhood pneumonia may also be mistaken for appendicitis.

• The elderly

The elderly are at higher risk of pneumonia.

• The chronically ill

Especially those with heart, liver or kidney conditions, asthmatics, people with smoker's lungs and diabetics.

• People with weak immune systems

People with weak immune systems such as HIV-infected individuals are at higher risk of pneumonia.

• Post-operation

People who have had their spleen removed are at higher risk of pneumonia.

• Alcoholics

Alcoholics and drug addicts are at higher risk of pneumonia.



Pneumonia diagnosis

The doctor will ask you questions about your illness, and then perform an examination of your chest, by tapping or 'percussing' it with his or her fingers and by using a stethoscope. The doctor will then listen for sounds that are not normally heard, like creaking and bubbling sounds when breathing.

In the majority of cases further investigation is not required. If however the doctor is particularly concerned about a patient, they will often be directed to their local hospital where some X-ray pictures of the lungs will be taken to see how bad the condition is.

Only if the condition was very severe, would they need to be admitted to hospital for treatment. If it were necessary, the micro-organism could be grown from your phlegm or your blood to find out what it is and decide the best course of treatment to take.



Pneumonia prevention

Smoking damages your lungs and makes them more likely to become infected. If you smoke, the best thing you can do to prevent pneumonia is to stop smoking.

All children are offered a pneumococcal vaccine as part of their routine childhood vaccinations. This vaccine protects against the most common kind of pneumonia, caused by the Streptococcus pneumoniae bacteria, known as pneumococcus.

If you are more than 65 years old, your immune system is relatively impaired, or if you suffer from a chronic disease such as smoker's lungs, asthma, a chronic heart, liver or kidney condition, or diabetes, you should also get vaccinated against pneumococcus.

If your spleen has been removed, for instance after a road accident, it is important to get a vaccination against pneumococcus.

Failure to get vaccinated means you run the risk of catching pneumonia. Around five years after the vaccination, your doctor needs to take a blood sample to see if it is still effective.



Pneumonia complications

The natural history of pneumonia varies, depending upon the person who catches it, the bacteria involved and the treatment provided.

In repeated cases of pneumonia and cases where the condition refuses to respond to a series of different treatments, there may be something else very seriously wrong like lung cancer.

Even following an episode of pneumonia that has been successfully treated, it is only natural to experience a period after the infection where you feel tired, get easily short of breath and have an annoying, persistent cough that can linger for several weeks.



Pneumonia treatment

Treatment for pneumonia depends on your age and if you have any other health problems:

• Mild pneumonia

Mild pneumonia can usually be treated at home by getting plenty of rest and drinking plenty of fluids. It is possible to treat pneumonia with antibiotics such as penicillin. If you do not have any other health problems, you should recover fairly quickly.

• Severe pneumonia

For at-risk groups including the elderly and people with a weakened immune system, pneumonia can be severe and may need to be treated in hospital. This is because pneumonia can lead to serious complications, which in some cases can be fatal, depending on a person's health and age.

⚠️ If you have been abroad within two to three months before contracting the disease, it is important that you tell your doctor right away. Foreign bacteria sometimes require a different treatment from those seen more commonly in the UK.

Last updated: 15-10-2019

Dr Roger Henderson is a Senior GP, national medical columnist and UK medical director for LIVA Healthcare He appears regularly on television and radio and has written multiple books.
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