Hello, You have left cheekbone injury which occurs due to inflammation leading to a collection of blood under the skin and forms hematoma. Need not to worry. I would suggest you apply warm compresses several times a day and you should take ibuprofen (if not allergic) or acetaminophen for pain and swelling. Avoid sun exposure. If it persists for more than a week, then consult an oral and maxillofacial surgeon for a proper evaluation to rule out a condition like a fracture or infection. The doctor may drain it or may prescribe ointment containing anticoagulant agent like heparin. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Harry Maheshwari