Fever can be one of the first symptoms of an infection somewhere in your body. It's a sign that your immune system is trying to fight off the infection.

Where infections commonly start

A fever in itself is not usually dangerous, but the infection that causes it can be. It's very important to tell your medical team if you develop a fever so they can treat the infection that is causing it.

An infection can occur anywhere in your body. The most common places are:

• the mouth and throat
• the skin
• the lungs
• the kidneys and bladder, especially if you have a catheter to drain urine from your bladder
• where a drip or central line goes in (cannula sites and PICC line sites)
• wounds and where wound drains go in
• ulcerating tumours
• the bloostream

Other less common places are the:

• liver and abdomen
• gullet (oesophagus)
• vagina and anus
• brain and spinal cord

Treating an infection

Treatment depends on the type of infection you have. We have a section on treating fever and infection.