Pneumonia is an infection of the lungs. It is usually caused by bacteria or a virus, and is often triggered by a cold or the flu.

Key points

  1. Anyone can develop pneumonia, but young people and the elderly are often worst affected.
  2. See your doctor if you have a chest infection which is not getting better.
  3. Most cases of pneumonia can be treated successfully at home with rest, plenty of fluids and a course of antibiotics.
  4. Hospitalisation may be advised for young children, the elderly or those with severe pneumonia.


Pneumonia is an infection that causes inflammation of the air sacs in one or both lungs. It is most commonly caused by one of the viruses or bacteria present in the air we breathe. Usually our bodies immune system is able to fight off these germs. But sometimes our immune system is overwhelmed, such as during a cold or a bout of the flu. When infection sets in, the air sacs in one or both lungs fills with pus and fluids, making breathing difficult.

Pneumonia can be caused by many types of germs, including:

  • Bacteria: the most common bacteria is Streptococcus pneumoniae (pneumococcus). There are many other types of bacteria that cause pneumonia.
  • Viruses: such as the flu virus, are also a common cause of pneumonia.
  • Fungi: pneumonia caused by fungal infections are relatively uncommon.

Bacteria is the most common cause of pneumonia in adults; whereas, viruses are the leading cause in children. Antibiotics can be used to treat pneumonia caused by bacteria, but are not effective if it is caused by a virus.

Who is at risk?

Anyone can develop pneumonia but the risk is greater in babies and children aged four years and under, and the elderly. Other risk factors include:

  • recently having had a cold or the flu
  • having a chronic lung condition
  • having a weakened immune system
  • drinking excessive alcohol or smoking
  • being a patient in hospital.

In children, the risk of pneumonia is increased by:

  • premature birth
  • poor nutrition
  • low birth weight
  • reduced rates of breastfeeding
  • exposure to tobacco smoke
  • lack of insulation and heating
  • living in damp, mouldy and/or overcrowded conditions.


The most common symptoms of pneumonia include:

  • cough (often with yellow or green coloured phlegm)
  • fever, which may be mild or high
  • shaking chills
  • shortness of breath
  • increased effort required to take a breath
  • low energy and fatigue
  • loss of appetite
  • headache
  • chest pain that gets worse when you breathe deeply or cough.

When to seek medical help

See your doctor if you have an ongoing chest infection that is not getting better. If your child develops a chest infection after a cold or the flu see your doctor straight away; children can become very sick very quickly if they develop pneumonia.

Seek medical assistance straight away if a bluish tinge develops in the skin, lips and nail beds. This is a sign that the lungs are unable to deliver enough oxygen to the body.


To diagnose pneumonia your doctor will take a medical history and do a physical exam. Pneumonia may be suspected if they hear coarse breathing, wheezing or crackling sounds when listening to the chest through a stethoscope.

To confirm a diagnosis of pneumonia a chest x-ray may be required to see which part of the lungs are affected. Blood tests and samples of fluid from the lungs may also be sent to the lab for testing.


Treatment varies depending on the type and severity of pneumonia you have, on your age and general physical well being.

Most cases of pneumonia can be treated at home. However, hospital admission is often recommended for babies, young children and the elderly, or for those who have severe pneumonia.

If treatment at home is advised:

  • rest as much as possible, in an upright position is best
  • drink plenty of fluids
  • take antibiotics if/as prescribed
  • take medications (such as paracetamol) if required for relief of pain and fever.

You are likely to need to see your doctor for a medical review at least once a day at first, and sometimes morning and afternoon, until you are clearly getting better. This includes weekends so you may have to attend an after hours clinic.

Self care

If you have pneumonia and your doctor advises that you can be treated at home, then you need to rest as much as possible. Make sure you are drinking enough fluids and eating healthy foods. It is also advisable to avoid smoking or passive smoking.

If possible, have someone stay with you or check in on you while you are unwell. Ensure you have access to a phone and are able to contact your doctor or emergency services if required. 


To help prevent pneumonia:

  • get a seasonal flu shot – it can help prevent pneumonia caused by the flu virus
  • get a pneumonia vaccination – this vaccine is especially recommended for anyone at high risk of pneumococcal pneumonia
  • wash your hands regularly or use an alcohol-based hand sanitiser
  • don't smoke – smoking damages your lung's ability to fight infection
  • stay rested and fit
  • stay home when you're sick
  • avoid people who have a cold or the flu.

Pneumonia vaccination

Three vaccines are available in New Zealand to prevent some forms of pneumonia:

  • All children should receive the pneumococcal vaccine Synflorix as part of the New Zealand Immunisation Schedule.
  • Another vaccine is used for children at high-risk of complications (funded for children aged under 5 years).
  • For all other high-risk people, vaccination is recommended, but not funded.

Learn more

Pneumonia - an overview NHS Choices, UK
Mayo Clinic, Mayo Foundation for Medical Education and Research, 2013
Pneumonia Kids Health NZ, Paediatric Society of New Zealand and Starship Foundation, 2014
Pneumonia – parent/caregiver informationCanterbury District Health Board, 2012 

Credits: Health Navigator.