Steroids are hormone. They can be naturally produced by the body or they can be artificially synthesised. So these artificially synthesised are of two types. One is known as corticosteroids which are medications for treating various illnesses and the other one is anabolic steroids taken by body builders and athletes to enhance their performances. Steroids are essential for sustenance of life. So they don’t generally cause side effects if taken for short duration or in low dosage. However if steroids are taken over a long period of time and in high dose, they can cause various side effects. Firstly it can cause disruption of hormones in both males and females. In men, generally it causes reduction of hormones leading to infertility. It can reduce the size of the testis or shrinkage of testis it can increase the size of the breast leading to gynecomastia and it can cause male pattern baldness because of the hormonal changes and in women it can induce masculine traits, like in women it can cause deepening of voice in women, it can affect the menstrual cycles, it can increase the hair growth on the face and the body, it can reduce the hair growth on the scalp leading to male pattern baldness. It can give rise to coarse thick skin in women. If steroids are taken during puberty, there can be reduction in growth spurt leading to short stature. It can affect the cardiovascular system if taken in high doses. It can cause something called as atherosclerosis or blockage of blood vessels because there is deposition of fatty substances. This can inturn lead to reduced blood supply to the heart, leading to heart attack or it can also cause reduced blood supply to the brain, which can lead to stroke. It can cause a variety of skin manifestations like thinning of skin, it can cause stretch marks, it can increase your acne, it can increase your rosacea, it can cause rashes around your lips. It can increase your facial hair, it can cause secondary infections, it can increase infections like bacterial infections, viral infections and a variety of infections. When taken in high doses, it can also cause various psychiatric manifestations like rage, depression, mania, it can reduce your appetite, your sex drive. Hence it is advised to take steroids under medical supervision only.