How is pneumonia diagnosed?

Your doctor will ask questions about your or your child’s health and any recent illnesses (for example a cold or flu), what your symptoms are, details of your medical history, if you have any other medical conditions and about any medicines you are taking.

The doctor will listen to your chest using a stethoscope (a medical device used to listen to your breathing and heart beat) and will probably take your temperature. Your doctor may also tap your chest and listen for sounds that may indicate there is fluid in your lungs.

Chest x-ray showing lungs with pneumonia

Chest X-ray showing pneumonia. Image: Carlos Gutierrez/

Normal chest X-ray

Normal chest X-ray. Image: Iwona Grodzka/


If your doctor suspects that you have pneumonia, you may need to have a chest X-ray to confirm the diagnosis. This is because pneumonia can share some of the symptoms of a cold, acute bronchitis and asthma.

A chest X-ray can show which of your lungs is affected (it may be one or both lungs), and how widespread any infection is in your lung(s).

If you have pneumonia, you will need to take antibiotics.

After your antibiotic treatment you may need another X-ray, especially if:

  • your symptoms have not improved, have worsened, or improved at first but have come back
  • you are 50 years or older
  • you smoke.

Read more about the treatments for adults and children with pneumonia and how to relieve the symptoms of pneumonia.

Laboratory tests

Sputum: your doctor may take a sample of your sputum. This will be sent to a laboratory and used to find out if bacteria are causing your infection and if so what type of bacteria.

Nasal or throat swab: a sample of cells taken from your nose or throat using a sterile cotton swab can be used to find out if a virus is causing your pneumonia (e.g. influenza virus).

Blood test: a blood sample may be taken to find out what is causing your infection.

Urine: a urine sample is sometimes used to help identify specific bacterial infections (e.g. caused by Streptococcus pneumoniae or Legionella pneumophila).

  • Antibiotic Expert Group. Community-acquired pneumonia in adults. In: eTG complete [online]. Therapeutic guidelines: antibiotic. Melbourne: Therapeutic Guidelines Limited; 2012. (Accessed 27 March 2012).
  • NHS Choices. Pneumonia – Treatment. (accessed 21 March 2012).