Some hematomas are visible under the surface of the skin (commonly called bruises) or possibly felt as masses/lumps. Lumps may be caused by the limitation of the blood to a sac, subcutaneous or intramuscular tissue space isolated by fascial planes. This is a key anatomical feature that helps prevent injuries from causing massive blood loss. In most cases the hematoma such as a sac of blood eventually dissolves; however, in some cases they may continue to grow such as due to blood seepage or show no change. If the sac of blood does not disappear, then it may need to be surgically cleaned out/repaired.
Regardless of how bad the injury is the PRICE principles of protection, rest, ice, compression and elevation should be applied as soon as possible. Apply a cold therapy and compression wrap immediately. Ice can be applied every two hours for 10 minutes for the first 72 hours for more severe contusions. This will help stop any internal bleeding and reduce pain and swelling. Wear a compression bandage or thigh support to protect the injury and help reduce swelling. Elevating the limb allows swelling and tissue fluids to drain away from the area.