Cystic acne is the largest and most painful form of acne, causing cysts deep beneath the skin. Cystic acne can be caused by hormones, genetics, and lifestyle factors like diet and stress.

Blind pimples, aka cystic acne, are painful zits that exist under the skin and never come to a head. To treat blind pimples, try benzoyl peroxide, a cold compress, and avoid attempting to pop it.

Inflammatory acne is the type in which bacteria inside a pore cause a red, swollen, pus-filled bump (pustule) on the skin. Cystic acne and nodular acne are two types of inflammatory acne.