I scraped my leg on a car door, now there's an oval shaped black&blue mark that developed a lump inside it w/swelling& numbness in my knee. do i worry?

Watch and wait: If the swelling is stable and numbness is not increasing, you may watch and wait. If it does not start improving in a couple of weeks, please consult your doctor. You may try warm compresses to hasten the resolution of the hematoma - collection of blood in the tissue.

If no sign of infect: ...ion, most likely an organizing hematoma. Numbness can B front injury 2 the superficial sensory nerves when scraped. Usually will run its course, though U may always have a small lump there. Ice, compression, elevate, later heat. If run fever or progresses C Ur PCP, numbness usually goes away or Ur brain gets tired of hearing about it & U won't notice it.