One way that it works is to decrease inflammation (swelling). It does this by preventing infection- fighting white blood cells (polymorphonuclear leukocytes) from traveling to the area of swelling in your body. (This is why you are more prone to infection while taking steroids). Taking advantage of the anti-inflammatory properties of the medication, corticosteroids are used to decrease the swelling around tumors. For example, by decreasing swelling around tumors in the spine, brain, or bone, it can decrease the pressure of the tumor on nerve endings and relieve pain or other symptoms caused by the pressing tumor.