We all know going to bed without taking off our makeup isn't great for us, but how bad exactly is it?
Pretty bad, according to BuzzFeed.
Watch the video above, or read on below, to find out why a quick face wash before hitting the hay is always in your skin's best interests.
Leaving foundation on skin can lead to acne, especially if it's oil based. A heavy coating may mean skin is unable to regenerate naturally - causing uneven skin tone, redness and dryness.
Not removing eye makeup can clog hair follicles and oil glands with bacteria causing inflammation or styes. Leaving on mascara can pull out some of your eyelashes while you sleep - plus, particles could get into your eye and increase the risk of corneal abrasion.
Lip products may cause blackheads by moving into your facial skin and clogging pores - especially true if you're a fan of Kylie Jenner-style over-lining. Wax substances in lip products can also cause them to chap.
During the day, free radicals in the environment cling to your makeup - sleeping in it means prolonged exposure to these free radicals, which may break down healthy collagen and wrinkles over time.