Some of the information in this article or section has not been verified and might not be reliable. It should be checked for inaccuracies and modified as needed, citing sources. Acne of a 14 year old boy during puberty. A close-up of a "whitehead" pimple. Take note of the inflammation surrounding it. A pimple is a type of skin lesion that is caused by inflamed and/or obstructed pores. The most common cause of pimples is acne; however, other causes, such as smallpox exist as well. ...
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From the EAST  traditional·alternative

Signs and symptoms
... Acne typically appears on your face, neck, chest, back, shoulders and scalp and can take the following forms: Whiteheads. These are created when the openings of hair follicles become clogged and block...
Source: MayoClinic

... Three factors contribute to the formation of acne: Overproduction of oil (sebum) Irregular shedding of dead skin cells resulting in irritation of the hair follicles of your skin Buildup of bacteria Ac...
Source: MayoClinic

Risk factors
... Hormonal changes in your body can provoke or aggravate acne. Such changes are common in: Teenagers, both boys and girls Women and girls, two to seven days before their periods Pregnant women People un...
Source: MayoClinic

When to seek medical advice
... Acne is rarely a serious medical condition. But you may want to seek medical treatment from a dermatologist for persistent pimples or inflamed cysts to avoid scarring or other damage to your skin. If ...
Source: MayoClinic