A deformity of the outer ear that may happen after an ear injury.

Cauliflower ear may happen after blood builds up under the skin of the outer ear after an injury. This is called a hematoma. Cauliflower ear can happen if the hematoma isn't drained well or becomes infected. Common causes include injuries from sports, such as wrestling, boxing or mixed martial arts.

If the injury that first caused the blood to build up isn't treated, cartilage in the outer ear may then scar and deform. This can lead to a misshapen ear.

If a health care provider promptly treats the injury, the provider may be able to remove the blood built up under the ear skin. If the injury isn't treated, surgery may be needed to fix scarring and deformity of the cartilage and restore the ear's shape. In some cases, the ear's shape may not be able to be restored.