Admit it -- if you wear makeup, at one point or another, you've probably gone to sleep with it on. Whether you forgot you were wearing it or you were just too tired to bother removing it, it happens. The important thing is to make sure it doesn't become a habit. Makeup is supposed to help you look and feel more beautiful, but leaving it on overnight often has the opposite effect.
Our skin is covered in pores, and those pores not only allow us to sweat, but they also allow us to secrete sebum, a waxy lubricant that helps moisturize and protect our skin. Sebum also helps remove dead skin cells and other irritants from pores in the process [source: Gordon]. The problem with makeup is that it clogs pores and prevents sebum from doing its job -- instead, sebum builds up, which can cause acne [source: Mayo Clinic].
If you want to avoid waking up to pimples, you need to remove your makeup each night before bed [source: Einstein]. You can use a makeup remover, facial cleanser, cold cream or toner to cleanse your skin and make sure it's free of makeup [source: Gordon]. And don't forget to remove your eye makeup as well. Leaving it on could cause contact irritation, an allergic reaction or even an infection [source: Beaver]. See a doctor if your eye becomes red, itchy or painful and you think it may be infected.
For more information on why you shouldn't sleep with makeup on, check out the links on the following page.