(HealthDay News) — Bruises occur when blood vessels below the skin rupture, says Cleveland Clinic. Most bruising is caused by minor accidents, medications and age. Bruises caused by minor injuries usually disappear within a week or two.

Cleveland Clinic suggests getting a bruise checked by your doctor if it:

  • Shows no signs of improvement after a week.
  • Is located on a part of your body where injury or accident is unlikely.
  • Keeps occurring or comes back.
  • Involves unusually large, unprovoked bruising.