Steroid injections, also called corticosteroid injections, are anti-inflammatory medicines used to treat a range of conditions.
Steroid injections are only given by healthcare professionals. Common examples include hydrocortisone, triamcinolone and methylprednisolone.
How steroid injections are given
Steroid injections are usually given by a specialist doctor in hospital.
They can be given in several different ways, including:
- into a joint (an intra-articular injection)
- into a muscle (an intramuscular injection)
- into the spine (an epidural injection ↗)
- into the blood (an intravenous injection)
The injections normally take a few days to start working, although some work in a few hours. The effect usually wears off after a few months.
If you're having an injection to relieve pain, it may also contain local anaesthetic ↗. This provides immediate pain relief that lasts a few hours.
You should be able to go home soon after the injection. You may need to rest the treated body part for a few days.
Side effects of steroid injections
Possible side effects of steroid injections depend on where the injection is given.
Side effects of injections into the joints, muscles or spine can include:
- pain and discomfort for a few days – paracetamol ↗ may help with this
- temporary bruising or a collection of blood under the skin
- flushing ↗ of the face for a few hours
- an infection, causing redness, swelling and pain – get medical advice as soon as possible if you have these symptoms
- a loss of fat where the injection was given – this can cause dimples in the skin and may be permanent
- paler skin around the site of the injection – this may be permanent
- if you have diabetes ↗, your blood sugar level may go up for a few days
- if you have high blood pressure ↗, your blood pressure may go up for a few days
Epidural injections can also very occasionally give you a pounding headache that's only relieved by lying down. This should get better on its own, but tell your specialist if you get it.
You can report any suspected side effect ↗ to a UK safety scheme.
Who can have steroid injections
Most people can have steroid injections.
Tell your doctor before having treatment if you:
- have had a steroid injection in the last few weeks – you usually need to wait at least six weeks between injections
- you've had three steroid injections in the last year – doctors usually recommend no more than three injections in the same area in the space of 12 months
- have had an allergic reaction to steroids in the past
- have an infection (including eye infections)
- have recently had, or are about to have, any vaccinations
- are pregnant, breastfeeding or trying for a baby
- have any other conditions, such as diabetes, epilepsy ↗, high blood pressure, or problems with your liver, heart or kidneys
- are taking other medicines, such as anticoagulants ↗
Steroid injections may not always be suitable in these cases, although your doctor may recommend them if they think the benefits outweigh any risks.
How steroid injections work
Steroids are a man-made version of hormones normally produced by the adrenal glands, two small glands found above the kidneys.
When injected into a joint or muscle, steroids reduce redness and swelling (inflammation) in the nearby area. This can help relieve pain and stiffness.
When injected into the blood, they can reduce inflammation throughout the body, as well as reduce the activity of the immune system, the body's natural defence against illness and infection.
This can help treat autoimmune conditions, such as multiple sclerosis (MS) ↗, which are caused by the immune system mistakenly attacking the body.