Facial hair is a secondary sexual characteristic in humans.
Unlike other animals, humans often shave their facial hair. When they leave it unshaven, they often style facial hair into moustaches, beards or sideburns.
In general, facial hair is thicker in men than in women. Many cultures seek to pretend that women have no facial hair. Excessive hairiness (especially facially) is known as hirsutism, and it can be a sign of serious hormone imbalance.
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