Whitehead: blocked pore, typically housing bacteria, skin oil and dead skin cells activating white blood cells to attach invading bacteria. Thus, giving the appearance of a whitehead. Squeezing or popping whiteheads can cause the spread of bacteria to other pores.

Blackheads: results of a partially blocked pore with trapped skin oil, bacteria and dead skin cells. Excess skin oil that drains to skin surface causes the skin to produce a black pigment melanin that reacts with the air causing black pore appearance.

Papule: are small red bumps without whiteheads. Papules are whiteheads that do not come to a head but remain below the pore surface. Avoid squeezing as it releases and spreads bacteria.

Pustule: are similar to whiteheads. Pustules are red swollen skin tissue with white or yellow centers a common variety of zits. Avoid squeezing as it releases and spreads bacteria.

Nodule: larger than papules lasting several months. Nodules are large hard bumps or lumps under the skin. Can cause extensive scarring if squeezed.

Cyst: large pus-filled cyst similar to a nodule measuring 5mm or more. Can cause extensive scarring if squeezed. Subject to long periods of healing.

Rosacea: similar to mild forms of acne but more severe. Confined to the face, typically exhibiting more redness or blemish areas. Rosacea is more common in women than men.

Conglobata: most severe form of acne and more common in males. Characterized by large lesions that are interconnected with blackheads. Can cause severe scarring. Onset is usually between 18 to 30 years of age and requires medical attention.