Acne is caused by the sebaceous gland’s overreaction to your hormones and the complex sequence of events that follow. In teens and young adults, high levels of hormones are needed for the rapid development of bones, muscle, and other tissues leading to adulthood. When the sebaceous gland overproduces sebum (the waxy oil that makes your face feel greasy), dead skin cells, makeup and dirt from the environment mix with the sebum forming a paste. This paste does not flow out of the pore easily so it fills up the pore. Bacteria in the dirt and on the skin consume this paste and grow out of control causing pressure in the pore which can lead to the rupture of the pore on the inside. Then the body’s immune system rushes in and begins the healing process by causing scarring making the skin tougher. After years of this process being repeated over and over in the same problem areas, serious scarring can form that may last your entire lifetime.