Knee bruises occur when small blood vessels beneath the surface of the skin break, allowing blood to leak into the soft tissue. This leads to discoloration, swelling and discomfort. The amount of pain and length of recovery depend on the severity and location of the bruise. Periosteal, or bone bruises, take the longest time to heal. Knee bruises that occur just beneath the skin -- subcutaneous bruises -- have the shortest recovery time. Bruises that occur in the muscles around the knees, called intramuscular bruises, are more painful than subcutaneous bruises.
Avoid painful activities until your knee pain decreases and it is no longer swollen. While some discoloration may linger while your injury is healing, these activities can worsen pain and swelling.
Apply a cold compress to your bruised knee to minimize swelling and promote healing. Use the compress for 10 to 15 minutes, every three to four hours. Do not apply ice directly to your skin -- this can cause tissue damage.
Prop your foot up on pillows when lying flat to raise your knee above the level of your heart. Elevation will reduce discoloration and swelling by preventing blood from pooling in the tissue around your knee.
Take acetaminophen for pain. Avoid aspirin or ibuprofen during the first hours unless your doctor tells you otherwise, as these medications can potentially worsen bleeding and bruising. Follow the dosing directions on the package.
Wear a compression garment on your knee to reduce swelling and speed recovery. Leave one finger-width between the garment and your skin to keep from wrapping too tightly.
Use crutches or other mobility aids as directed by your doctor. Be very careful when walking up and down stairs to prevent reinjury of your knee.