Brazilian jiu-jitsu
Cauliflower ear

Due to the use of the head to maintain position and attack in jiu-jitsu, the ears can easily be damaged and begin to swell. Without immediate medical treatment, the cartilage in a swollen ear will separate from the perichondrium that supplies its nutrients and will become permanently swollen/deformed (cauliflower ear). Wrestling headgear is sometimes used for the prevention of this condition. Treatment includes draining the hematoma or surgery.
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