Why is corticosteroid used in a cortisone injection?

Inflammation can make nearby tissues sensitive and swollen, which may restrict movement and amplify pain. A corticosteroid is an anti-inflammatory medicine delivered close to the area being treated. The injection may also contain a local anaesthetic, which can provide short-term numbness and help the clinician identify whether the targeted area contributes to your symptoms. The two medicines have different jobs.

The injection is intended to ease symptoms so that movement, sleep or rehabilitation may become more manageable. It does not rebuild worn cartilage, repair every tendon injury or correct the underlying cause in every case. The likely benefit depends on the diagnosis, the tissue involved and your general health.

Before the injection, tell the clinician about diabetes, infection, allergies, blood-thinning medicines and previous reactions to injections. Follow the advice about resting the treated area and returning to activity. A temporary flare of soreness can occur after the procedure; use only the pain relief and cold or heat measures recommended for you. Keep any follow-up appointment so the diagnosis and next treatment step can be reviewed.

Get medical advice promptly if the injection site becomes increasingly red, hot, swollen or draining, or if you develop fever or feel unwell. Seek urgent help for facial swelling, widespread hives or trouble breathing. New severe pain, marked weakness or loss of movement also needs prompt assessment.

What structure are you targeting, and what inflammation is suspected? What medicine will be injected with the corticosteroid? How should I change activity afterward? Which symptoms mean I should contact you? What alternatives are suitable if the injection does not help?