Corticosteroids mimic endogenous steroid hormones like cortisol and aldosterone. They have anti-inflammatory and metabolic effects and come in both short-acting and long-acting forms with varying potencies. Dosage levels range widely depending on the condition being treated, from low maintenance doses to high doses for critical illnesses. Side effects become more likely at higher doses or longer durations and include issues like weight gain, increased risk of infection, and bone loss, so the goal is to use the minimum effective dose and taper off treatment when possible.