Symptoms of infection

Infections can sometimes be life threatening. A fever may be the first or only sign of an infection. But with some infections, you may have other symptoms without a fever.

Treating an infection early can stop it becoming a more serious problem. Tell your healthcare team immediately about any symptoms. Even if it turns out that you don’t have an infection it’s better to find out as soon as possible.

Signs and symptoms of an infection

There are several symptoms you might have when you have an infection. Call your 24 hour advice line straight away if you have any of these:

• feeling generally unwell – not able to get out of bed

• a temperature of 37.5°C or above

• a temperature below 36°C

• flu-like symptoms – feeling cold and shivery, headaches, and aching muscles

• coughing up green phlegm

• a sore throat or sore mouth

• a throbbing, painful tooth

• pain having a wee, going more often or cloudy or foul-smelling wee

• diarrhoea – 4 or more loose, watery bowel movements in 24 hours

• skin changes – redness, feeling hot, swelling or pain

• a fast heartbeat

• feeling dizzy or faint

• being sick (vomiting)

• a headache

• pain, redness, discharge, swelling or heat at the site of a wound or intravenous line such as a central line or PICC line

• pain anywhere in your body that was not there before your treatment

It is important to start treatment if it’s needed as soon as possible. This reduces the risk of an infection developing into sepsis.

What is sepsis?

Sepsis is a serious complication of an infection that can be life threatening. 

The following symptoms could be due to sepsis. Call 999 or go to your local Accident and Emergency (A&E) immediately if you have any of the following:

• Slurred speech or confusion
• Extreme shivering or muscle pain
• Passing no urine (in a day)
• Severe breathlessness
• It feels like you’re going to die 
• Skin mottled or discoloured

Medicines that mask or bring down a temperature

Some types of painkillers such as paracetamol and ibuprofen are anti pyretics. This means they bring down temperatures. Taking these may disguise that you have an infection. Taking steroids can also hide the signs of infection.

Where infections commonly start

A fever in itself is not usually dangerous, but the infection that causes it can be. 

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 bloodstream

Other less common places are the:

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

What you can do

You can’t always prevent an infection. The most important thing you can do is contact your advice line, or depending on your symptoms – call 999 or go to A&E. But there are things you can do to help yourself and reduce your risk of getting an infection.

Before Treatment

• Have a dental check.

• Buy a thermometer and make sure you and your friends and family know how to use it.

• Talk to your healthcare team about vaccines you should have. For example, the flu vaccine and Coronavirus (COVID-19) vaccine.

• Make sure you and your family and friends are familiar with the symptoms of an infection and sepsis. Let everyone know about the advice line.

Your hospital may give you an alert card explaining the symptoms and what to do.

During treatment

• Try to avoid people who are unwell or have an infection. For example, people with chest infections, diarrhoea, and chicken pox.
• Brush your teeth with a soft toothbrush at least twice a day and preferably after every meal and at bedtime.
• Tell your doctor if you have any ulcers or pain anywhere in your mouth.
• Wash your hands before eating or handling food, after using the toilet, and after contact with animals.
• Protect your skin from scratches. You can do this by wearing gloves and keeping your arms and legs covered when you are gardening. If you do cut or graze your skin, wash the area thoroughly with warm water and soap. You can put antiseptic cream over the area and cover it with a plaster. 
• Store, prepare, and cook food following the correct instructions.

Don’t be afraid to live your life as normal. You do not need to stop seeing family and friends unless they have an infection or feel unwell. You don't need to avoid crowded places unless specifically advised to do so by your healthcare team.

Treating an infection

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