Steroids are hormones that occur naturally in the body. Steroid medicines are man-made and are similar to the natural hormones made in the body. Reversing enlargement of blood vessels in the area they are applied to. They cause a narrowing of the blood vessels. Steroid injections birey be very effective https://lhcathome.cern.ch/lhcathome/show_user.php?userid=2133820