According to WebMD, the fastest way to reduce swelling is to elevate the injured area and apply a cold compress. Elevating an area that is swollen requires the area to be above heart level. This is achieved by lying down and elevating the swollen area of the body with pillows.
Mild swelling usually goes away on its own, according to WebMD. However, a doctor is needed if the swelling increases or spreads to other areas of the body. A doctor also needs to be notified if the symptoms of the swelling become more severe or if other symptoms develop, such as fever, pain, a decrease in urination or trouble breathing.