What is acne?
Acne is a common skin condition causing pimples and blackheads. These appear during adolescence when the skin produces large amounts of an oily liquid called sebum. The skin’s pores can become blocked, and the sebum builds up to produce a pimple or a blackhead. Sometimes the trapped sebum becomes infected and causes an inflamed spot, which is acne.
What is a bruise?
Bleeding under the skin after a knock causes bruises. The blood spreads in the tissues beneath the skin, and at first look purplish. As the red blood cells break down and become absorbed into the bloodstream, the bruise changes colour before disappearing.
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