Acne is definitely a four-letter word for people who suffer with it. It is an inherited disorder of the pores – pores that want to sludge up with dead skin cells much like a clogged drain in your sink. Normal pores shed about one layer of dead skin cells per day inside the pore. The acne-prone pore sheds up to five layers of dead skin cells per day and the body just can’t keep up. This forms congestion under the skin which are noninflamed acne lesions (blackheads and/or whiteheads; and if bacteria are present (which just loves to feed on the dead skin cells and oil), you will get inflamed pimples, pustules and/or cysts. For a more in-depth explanation of how acne is formed, go here: How Acne Forms
There are two main types of acne as we see it – noninflamed acne and inflamed acne. Most people have a combination of the two.