So what exactly are whiteheads and blackheads? The short answer is that whiteheads and blackheads are two types of acne that are the nightmare of millions of teenagers, and even a great many adults. The long answer requires a more in-depth explanation.

That explanation should begin with an understanding of where exactly acne comes from and what happens during the process that makes whiteheads and blackheads appear differently. Acne originates in the skin’s pores where hair follicles are located. According to the Food & Drug Administration, there are sebaceous glands within these follicles (located near the base of the hair) that are responsible for production of a natural oily substance called sebum. The body’s hormones sometimes stimulate over-production of sebum and the body cannot naturally get rid of it quickly enough, causing the pores to clog.

The pores clog with sebum, dead skin cells (which are shed faster by people with acne), keratin (a common ingredient in hair, fingernails, etc.) and bacteria that feeds off these things. When the materials clogging the pore reach the surface of the skin, the reaction of light with the pigment in the pores causes a black appearance, and a blackhead is formed.

Sometimes the clog occurs beneath the skin’s surface and the body’s immune system tries to kill the bacteria with white blood cells that also mix with all of the pollutants clogging the pore. The end result is the formation of a bubble that contains the pore-clogging stew, or a whitehead. Sometimes the head will rupture beneath the skin’s surface and spread to other tissue, infecting it. This is essentially how more serious acne, with nodules and cysts, forms.

As you can see, not all acne is the same. Some just reaches the skin’s surface, some protrudes beyond it, and some never really reaches the surface at all. These different manifestations of acne are a major reason that there are so many different types of acne treatment available on the market.