This article contains an over view Corticosteroids and especially Harmful effects of Corticosteroids on short term and long term use. Corticosteroids have numerous applications as, anti inflammatory, immune response, anti cancer agent, allergic response and for asthma like this. Along with the multipurpose use there are some adverse effects with chronic use. Minimum adverse effects are growth retardation in children, Hypertension, ImmunoSupression, Severe asthma, Inhibition of wound repair, hyper glycemia, Osteoporosis, Glucoma, Metabolic disturbance and Cataracts. Cognitive shortage following acute administration of CS (Corticosteroids) on humans. In serious Psychiatric disorder, insomnia, agitation Oral clefts to born babies when mother consumed CS during pregnancy of first trimester, Fetal deaths on some cases. The effect of CS is based on doses and period they are using. Risk factors are low when doses are mild and risk or adverse effects are high when prolonged periods or using high doses.