Fever and infection
Fevers caused by the cancer itself often stop when you have successful cancer treatment.
Your doctor will also try to relieve your fever symptoms.
Read more about fevers caused by cancer
The treatment you have depends on the type of infection you have.
Bacterial infections are usually treated with antibiotics. They kill the bacteria or prevent them from spreading around the body. You have blood tests and possibly some swabs if your doctor thinks you might have an infection.
You will start a course of broad spectrum antibiotics. These are antibiotics that can fight a wide range of different infections. It's very important to treat the infection quickly, so you may start antibiotics while you wait for the results of any tests.
Your doctor may know more about what is causing your infection when your test results come back. This can sometimes take a few days. Your doctor will change the antibiotics you are taking if they are not right for the infection you have.
You might continue with broad spectrum antibiotics. This is to try and prevent other infections from developing.
You're most likely to have antibiotics into a vein (intravenously) if you have an infection while you have a low white cell count. You have them until the signs of infection have gone.
Antibiotics can also be given:
by mouth - with tablets, capsules, or liquids
by injection into a muscle
topically- these are creams and lotions you put on and around the skin in the area of infection
There are many different broad spectrum antibiotics. Your doctor will tell you what antibiotics you will have and the possible side effects.
Some viral infections are treated with antivirals.
Aciclovir is a drug for viral infections, such as herpes simplex or varicella zoster.
Drugs called ganciclovir and foscarnet (Foscavir) can treat a virus called cytomegalovirus. Foscarnet is also useful in treating the herpes simplex virus that is not responding to aciclovir.
Fungi can live in our bodies without usually causing any problems. But it can cause problems if a fungal infection occurs when your immune system is weak.
A common fungal infection in people with cancer is Candida (thrush). You're more at risk from oral (mouth) thrush if you have a sore mouth from chemotherapy or radiotherapy. You may notice white patches with red and sore skin underneath.
Fungal infections are treated with antifungal drugs, for example, nystatin or fluconazole. Your healthcare team will tell you more about any antifungal treatment if you need it, including the side effects.
Your nurse stops your blood transfusion straight away if you have a reaction to the blood. For example, a high temperature. You might need to have other medication to stop the reaction.
Fever caused by side effects of drugs is treated by stopping or changing your medication.
You usually have to go to hospital for tests and an assessment. You might need to stay in hospital for your treatment.
People with a low risk of becoming very unwell from an infection might be able to go home and take tablets to treat the infection. Your healthcare team looking after you will let you know if this is suitable for you. They will also tell you what to look out for and what to do if you do become unwell.
It's very important that you call your hospital advice line or go back to the hospital straight away if you do have any problems.
You might have antibiotics to try to help prevent infections, if you have a low white blood cell count. These are called prophylactic (pronounced prof-ill-ak-tick) antibiotics.
You might have growth factor drugs. Growth factors are natural substances that stimulate the to make blood cells. Some of these substances are now made artificially. You have them to increase the number of white blood cells and stem cells in the blood. This can reduce the time you are at risk of infection when having chemotherapy.
Not everyone on chemotherapy needs growth factor injections. It depends on your disease and the effects of the chemotherapy treatment you are having.
Read more about the growth factor G-CSF
A fever can make you feel hot, cold, shivery, washed out and sometimes have aches and pains.
As well as treating the cause of an infection, you need treatment for your fever symptoms. This helps to make you more comfortable. Bringing your temperature down can make a difference to how you feel.
You might have paracetamol. This can help relieve aches and pains. It is also an antipyretic. This means it brings down your temperature.
You usually take them regularly, every 4 to 6 hours, until you no longer have a high temperature. Make sure you read the drug information leaflet so that you know what dose to take and when.
You might take steroids, for example, if your fever has been caused by a reaction to treatment.
Aspirin and ibuprofen can reduce your temperature, but you shouldn't take them without checking with your doctor. You shouldn't have it if you have a low platelet count or any other risk of bleeding. For example, a stomach ulcer. This is because they can affect the time it takes your blood to clot.
Find out more about these drugs
Other things that can make you feel more comfortable include:
removing excess clothing and bed linen
having a lukewarm (tepid) bath or sponge down
drinking cool fluids, such as water and sucking ice chips
opening the window or having a fan in the room
during periods of chills, change any wet bed linen and clothes to keep you warm and dry, and keep away from drafts
rest as much as you can
Even if you have a high temperature, you might feel cold and begin to shiver. Your immediate reaction may be to use blankets to feel warm. But even though you feel cold, inside your body is very hot.
You will generally start to feel better when your temperature comes down.
Last reviewed: 18 Mar 2026
Next review due: 19 Mar 2029
A number of things can cause fever. This can include some cancers, drugs, and other treatments.
Fever can be caused by infection. Find out what symptoms to look out for and the different types of infection.
Having a fever means your body temperature is higher than normal. Something inside your body, such as an infection, has caused your temperature to rise.
Coping with cancer can be difficult. There is help and support available. Find out about the emotional, physical and practical effects of cancer and how to manage them.
Find out about managing cancer symptoms and possible side effects from cancer treatment. There is information about pain, sickness, diet problems and much more.

About Cancer generously supported by Dangoor Education since 2010. Learn more about Dangoor Education
Search our clinical trials database for all cancer trials and studies recruiting in the UK.
Connect with other people affected by cancer and share your experiences.
Questions about cancer? Call freephone 0808 800 40 40 from 9 to 5 - Monday to Friday. Alternatively, you can email us.