What are steroids?

Steroids are substances that are naturally produced in the body. They help to control many of the different ways our bodies work. They regulate:

  • the way the body uses fats, proteins and carbohydrates
  • the immune system
  • the balance of salt and water in our bodies
  • inflammation.

Steroids can also be made in a laboratory as drugs. They can be used in cancer treatment: 

  • to help destroy cancer cells and make other cancer treatments more effective
  • to prevent or treat an allergic reaction 
  • as anti-sickness drugs
  • to improve appetite
  • to reduce cancer symptoms, such as pain caused by swelling (inflammation) around a tumour
  • to treat inflammation caused by cancer treatment.

The most commonly used steroids are:

  • hydrocortisone
  • dexamethasone
  • methylprednisolone 
  • prednisolone.

More information about this treatment

This information is correct at time of publishing. But sometimes the types of cancer this treatment is used for, or treatment side effects, may change between revision dates.

You can talk to your cancer team if you want more detailed information about this treatment. Or visit the electronic Medicines Compendium (eMC) website, which has patient information leaflets (PIL) for individual drugs.

How steroids are given

This information is about steroids that you take by mouth or as an injection. Steroids also come in other forms, such as inhalers, eye drops or creams. If you are having steroids in these ways, your doctor, nurse or pharmacist can give you more information. 

You usually have steroids as tablets that you swallow. If you have difficulty swallowing, your doctor may prescribe steroid tablets that dissolve in water. Some steroids also come as a liquid syrup. 

You can also have steroids as an injection. 

The dose you have and how long you have the treatment for depends on the reason you are taking steroids. 

Tablets or liquids

You usually take steroid tablets or liquids at set times each day for a number of days or weeks. It is important to make sure you know how long to take them for. Take them exactly as your doctor, nurse or pharmacist explains. Do not stop taking them without talking to your doctor first. Do not take them for longer than you have been told to.

Swallow the steroid after food, or with plenty of water. 

Other things to remember about steroid tablets or liquids:

  • Keep the tablets or liquid in a safe place and out of the sight and reach of children.
  • If your doctor decides to stop the treatment, return any remaining tablets or liquid to the pharmacist. Do not flush them down the toilet or throw them away.
  • If you are sick just after taking the steroid, tell your doctor. You may need to take another one.
  • If you forget to take your tablet or liquid, do not take a double dose. Ask your doctor or nurse for advice. 
  • If you have a short course of steroids as part of your treatment, do not get more from your GP.


Steroids can be given by injection in the following ways:

  • into a muscle (intramuscularly)
  • under the skin (subcutaneously)
  • into a vein (intravenously).

If steroids are given into a vein, you have them as a quick injection or as a drip over a longer period of time. They can be given through:

  • a cannula – a short, thin tube the nurse puts into a vein in your arm or hand
  • central line – a fine tube that goes under the skin of your chest and into a vein close by
  • PICC line – a fine tube that is put into a vein in your arm and goes up into a vein in your chest
  • an implantable port (portacath) – a disc that is put under the skin on your chest or arm and goes into a vein in your chest.

About side effects

We explain the most common side effects of this treatment here. We also include some that are less common. 

You may get some of the side effects we mention, but you are unlikely to get all of them. And you may have some side effects, including rarer ones, that we have not listed here. 

Other cancer treatments may cause different side effects. If you are also having other cancer treatment, you may have other side effects.

Always tell your doctor, nurse or pharmacist about any side effects you have. They can give you: 

  • drugs to help control some side effects 
  • advice about managing side effects. 

It is important to take any drugs exactly as explained. This means they will be more likely to work for you.

Serious and life-threatening side effects

Some cancer treatments can cause serious side effects. Sometimes, these may be life-threatening. Your doctor, nurse or pharmacist can explain the risk of these side effects to you.

Contact the hospital

Your doctor, nurse or pharmacist will give you 24-hour contact numbers for the hospital. If you feel unwell or need advice, you can call at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.

Side effects while treatment is being given

When a steroid is given into a vein quickly, it can cause a strange sensation in the area just in front of your back passage (the perineal area). This only lasts for a few seconds.

Possible side effects

Tummy pain or indigestion

Steroids can irritate the stomach lining. If you have indigestion or pain in your tummy, let your nurse or doctor know. They can prescribe drugs to help reduce stomach irritation.

To help protect your stomach, you should take your tablets with food. Some steroid tablets are coated to help reduce irritation.

Raised blood sugar levels

Steroids can raise your blood sugar levels. Your nurse will check your blood regularly for this. They may also test your urine for sugar. If you have a raised blood sugar level, you may: 

  • feel thirsty
  • need to pass urine more often 
  • feel tired. 

Tell your doctor or nurse if you have these symptoms.

If you have diabetes, your blood sugar levels may be higher than usual. Your doctor will talk to you about how to manage this. You may need to change your insulin or tablet dose.

Fluid build-up

This treatment can cause a build-up of fluid in the body. This will slowly get better after treatment ends. Contact the hospital on the 24-hour number if you:

  • are gaining weight 
  • have swelling in your face, legs or ankles.

They can give you advice and treatment to help.

Increased appetite

Steroids can make you feel hungrier than usual and you may gain weight. This is useful if you have a poor appetite. But it can be an unwanted side effect for some people. Your appetite should go back to normal when you stop taking steroids. If you are worried about gaining weight, talk to your doctor or nurse. 

Increased risk of infection

If you have high-dose steroids, or steroids and other cancer treatments at the same time, you may have an increased risk of infection. Tell your doctor if you notice signs of infection. This can include a cough, a sore throat or a temperature above 37.5°C. 

To reduce the risk of getting an infection: 

  • wash your hands thoroughly before eating, and after using the toilet  
  • avoid people with an infection, such as a cold
  • avoid crowds or public places where there is a risk of getting an infection.

Changes to your periods

If you have periods, these may become irregular or stop during treatment. Periods usually return to normal once treatment has finished. This also depends on what other cancer treatments you have, such as chemotherapy.

Mood and behaviour changes

Steroids can affect your mood and behaviour.  They can cause:

  • feelings of anxiety or restlessness
  • mood swings (moods that go up and down)
  • low mood or depression.

Sometimes, when taken in higher doses, steroids can cause confusion or changes in thinking. This can include having strange or frightening thoughts.

If you notice any changes in your mood or behaviour, tell your doctor or nurse. They may make some changes to your treatment if the side effects are causing you problems.

Difficulty sleeping

Some people find it more difficult to sleep while taking steroids. Taking your steroids in the morning may help. If you take steroids twice daily, you could take them in the morning and early afternoon.

Less common side effects

These less common side effects may develop if you need to take steroids over several weeks or months. Your doctor, nurse or pharmacist can talk to you about your treatment plan.  

Eye changes

Steroids can cause eye problems. There is also an increased risk of eye infections. Tell your doctor, nurse or pharmacist if you notice any changes to your eyes such as:

  • blurred vision
  • pain
  • redness.

Effects on the skin, hair and face

Steroids can cause changes including:

  • acne
  • a puffy face
  • unwanted facial hair
  • stretch marks or changes in skin colour
  • thin, fragile skin that bruises easily or takes longer to heal. 

If you have any of these side effects, talk to your doctor. The side effects may be reduced by lowering the dose of steroids. 

Effects on muscles

Your muscles may become weaker while you are taking steroids. You may find it more difficult to climb the stairs, lift things or reach above your head.

If you notice these changes, tell your doctor or nurse.  

Bone thinning (osteoporosis)

If you are at risk of bone thinning, your doctor may prescribe drugs called bisphosphonates to protect your bones. They will also usually give you advice about taking vitamin D supplements and your diet. 

Doing regular exercise, such as walking, can improve your bone health. Eating a healthy diet can help too. We have more information about bone health and looking after your bones

If you have any pain in your bones, such as in your lower back, tell your doctor.

Other information

Your steroid emergency card

You should be given a steroid emergency card if you are taking: 

  • high doses of steroids
  • steroids for longer than 4 weeks
  • repeated courses of steroids. 
You should always carry this card. In an emergency, it shows any doctor treating you that you are having steroid treatment. The doctor needs to know this because:
  • stopping your steroid treatment or missing a dose may make you unwell
  • your body may not naturally make extra steroids that are needed during a serious illness or after an injury.  

Stopping a longer course of steroids

It is important to take steroids exactly as prescribed by your doctor.

After you stop taking steroids, your body starts making its own steroids again. But it can take a few days for this to happen. If steroid treatment is suddenly stopped, you may have withdrawal effects. These include:

  • a fever
  • aching muscles or bones
  • feeling generally unwell.

To prevent this, your doctor may gradually reduce the dose. This gives your body a chance to adjust and get used to making its own steroids again.

Medical and dental treatment

If you need medical treatment for any reason other than cancer, always tell the healthcare professional that you are having cancer treatment. Give them the contact details for your cancer doctor or cancer team so they can ask for advice.

If you have appointments with a dentist, always tell them you are having cancer treatment. Talk to your cancer team before you have any dental treatment.

About our information

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert health professionals and people living with cancer.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

The language we use

We want everyone affected by cancer to feel our information is written for them.

We want our information to be as clear as possible. To do this, we try to:

  • use plain English
  • explain medical words
  • use short sentences
  • use illustrations to explain text
  • structure the information clearly
  • make sure important points are clear.

We use gender-inclusive language and talk to our readers as ‘you’ so that everyone feels included. Where clinically necessary we use the terms ‘men’ and ‘women’ or ‘male’ and ‘female’. For example, we do so when talking about parts of the body or mentioning statistics or research about who is affected.

You can read more about how we produce our information here.

Date reviewed

Reviewed: 01 February 2022
Next review: 01 August 2025
Trusted Information Creator - Patient Information Forum
Trusted Information Creator - Patient Information Forum

Our cancer information meets the PIF TICK quality mark.

This means it is easy to use, up-to-date and based on the latest evidence. Learn more about how we produce our information.