A bruise occurs when capillaries (small blood vessels) break and bleed into the surrounding tissue. According to the National Institutes of Health, a bruise can occur underneath the skin, within the belly of a muscle or within a bone. Most bruises heal on their own; however, a bruise can result in compartment syndrome. Compartment syndrome is an increase in pressure that can decrease the blood supply to tissues or organs around the bruise. You will notice excessive pain, swelling, numbness, tingling or weakness in your lower limb if compartment syndrome develops because of a deep bone bruise of the knee. This complication is life threatening, and you should seek immediate medical treatment. Use the following guidelines to promptly treat a deep bone bruise of the knee.
Elevate the injured knee above the level of your heart, advises the Mayo Clinic. Lie down and place your knee and foot on a pillow so that your entire lower leg is elevated to ease swelling.
Apply an ice pack to the bruised knee for 20 minutes. Remove the ice pack for 20 minutes. Repeat this cycle several times during the day to reduce pain and swelling in the knee.
Consider taking over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs), such as Aleve, ibuprofen or Motrin, to reduce pain and swelling. Follow the instructions on the drug label and use as directed. Consult your doctor about taking these medications.
Rest the bruised knee as much as possible. Avoid using crutches, if possible, to prevent the knee from becoming stiff.
See your doctor if you have extreme pain or an unusually large bruise, if you heard a "pop" or a "snap," if you have a history of a bleeding disorder or if you are bleeding from other areas of your body.