Acne is a skin condition that occurs when your hair follicles become plugged with oil and dead skin cells. It causes whiteheads, blackheads, or pimples. Acne is most common among teenagers, though it affects people of all ages.
Effective acne treatments are available, but acne can be persistent. The pimples and bumps heal slowly, and when one begins to go away, others seem to crop up.
Depending on its severity, acne can cause emotional distress and scar the skin. The earlier you start treatment, the lower your risk of such problems.
Symptoms
Acne signs vary depending on the severity of your condition:
* Whiteheads (closed plugged pores)
* Blackheads (open plugged pores)
* Small red, tender bumps (papules)
* Pimples (pustules), which are papules with pus at their tips
* Large, solid, painful lumps under the skin (nodules)
* Painful, pus-filled lumps under the skin (cystic lesions)
Acne usually appears on the face, forehead, chest, upper back, and shoulders.
When to see a doctor
If self-care remedies don’t clear your acne, see your primary care doctor. He or she can prescribe stronger medications. If acne persists or is severe, you may want to seek medical treatment from a doctor who specializes in the skin (dermatologist or pediatric dermatologist).
For many women, acne can persist for decades, with flares common a week before menstruation. This type of acne tends to clear up without treatment in women who use contraceptives.
In older adults, a sudden onset of severe acne may signal an underlying disease requiring medical attention.

Causes of Acne

Four main factors cause acne:
* Excess oil (sebum) production
* Hair follicles clogged by oil and dead skin cells
* Bacteria
* Inflammation
Acne typically appears on your face, forehead, chest, upper back, and shoulders because these areas of skin have the most oil (sebaceous) glands. Hair follicles are connected to oil glands.
The follicle wall may bulge and produce a whitehead. Or the plug may be open to the surface and darken, causing a blackhead. A blackhead may look like dirt stuck in pores. But actually, the pore is congested with bacteria and oil, which turns brown when it’s exposed to the air.
Pimples are raised red spots with a white center that develop when blocked hair follicles become inflamed or infected with bacteria. Blockages and inflammation deep inside hair follicles produce cystlike lumps beneath the surface of your skin. Other pores in your skin, which are the openings of the sweat glands, aren’t usually involved in acne.
Certain things may trigger or worsen acne:
Hormonal changes. Androgens are hormones that increase in boys and girls during puberty and cause the sebaceous glands to enlarge and make more sebum. Hormone changes during midlife, particularly in women, can lead to breakouts too.
* Certain medications. Examples include drugs containing corticosteroids, testosterone, or lithium.
* Diet. Studies indicate that consuming certain foods – including carbohydrate-rich foods, such as bread, bagels, and chips – may worsen acne. Further study is needed to examine whether people with acne would benefit from following specific dietary restrictions.
* Stress. Stress doesn’t cause acne, but if you have acne already, stress may make it worse.