As corticosteroids are hormones, they can have a wide range of side effects. This is because hormones are powerful chemicals that influence many different processes, from the strength of your bones to your body weight.

If you are prescribed corticosteroids, the range and severity of the side effects will depend on two factors:

• what type of corticosteroid medicine you are taking, and
• how long you are using it for.

With inhaled corticosteroids or corticosteroids injected into a muscle or joint, the effects are focused in one part of the body. So any side effects also tend to be limited to a single part of the body.

With oral corticosteroids, or corticosteroids that are injected into the blood, the effects are spread throughout the body.

Long-term corticosteroid use is more likely to lead to hormonal changes within the body, which can cause a wide range of side effects.

Inhaled corticosteroids

The short-term use of inhaled corticosteroids means that most people will tolerate them well and have few or no side effects.

Long-term use, to treat a chronic condition such as asthma, can cause oral thrush (fungal infections that develop inside your mouth).

Rinsing your mouth out with water after using inhaled corticosteroids can help to prevent oral thrush.

Injected corticosteroids

Corticosteroids injected into muscles and joints may cause some pain and swelling at the site of the injection. However, this should pass within a few days.

Over time, repeated steroid injections into a muscle can weaken it.

Intravenous corticosteroids (injected into the blood) can cause side effects including:

• stomach irritation, such as indigestion or heartburn,
• tachycardia (rapid heartbeat),
• nausea,
• insomnia, and
• a metallic taste in the mouth.

You may also experience mood changes. You could go from feeling very happy one minute to being irritable, depressed or restless the next.

Oral corticosteroids

Side effects of oral corticosteroids that are used on a short-term basis include:

• an increase in appetite,
• weight gain,
• insomnia,
• fluid retention, and
• mood changes, such as feeling irritable, or anxious.

Side effects of oral corticosteroids used on a long-term basis (longer than three months) include:

• osteoporosis (fragile bones),
• hypertension (high blood pressure),
• diabetes,
• weight gain,
• increased vulnerability to infection,
• cataracts and glaucoma (eye disorders),
• thinning of the skin,
• bruising easily, and
• muscle weakness.

Even if your side effects become troublesome, do not suddenly stop taking your medication. While you are taking steroids, your body will reduce the production of natural steroids.

If you do suddenly stop taking them, your body will not have enough steroids to work properly, and it is likely that you will have symptoms such as:

• fatigue,
• weight loss,
• nausea,
• dizziness,
• vomiting,
• diarrhoea, and
• abdominal pain.

If a decision is made to end your treatment, your doctor will gradually reduce the amount of corticosteroids that you are taking.

The best way is to reduce the workload of the patient so that the body would have the opportunity to increase its production of natural steroids.