Corticosteroid
A medicine that suppresses inflammation and immune activity.
What it means
Corticosteroids are synthetic versions of cortisol, the body's own steroid hormone, used to suppress inflammation and immune activity.
They are not anabolic steroids. Anabolic steroids are testosterone derivatives used to build muscle; corticosteroids do the opposite, breaking down muscle over time. The shared word causes real and avoidable anxiety.
Given as tablets, injections, inhalers, nasal sprays, creams, eye drops and enemas. Route determines risk: an inhaled or topical steroid carries a small fraction of the systemic effects of the same drug taken by mouth.
In practice
Topical steroid creams are graded from mild (hydrocortisone) to very potent, with potency matched to the site — mild only on the face and in skin folds.
Undertreating eczema through fear of steroids is more common than overtreating it, and prolongs the flare.
Why it matters
Steroid tablets taken for more than about three weeks must not be stopped suddenly. The body's own cortisol production shuts down and takes time to restart. The dose is reduced gradually.
Anyone on long-term steroids should carry a steroid emergency card and know that the dose may need increasing during illness, surgery or injury.
Clinically reviewed by Dr Mohammad Zubair Khan, GMC 7563469
Last reviewed
August 30, 2026