• Pustule
• Whiteheads
• Blackheads
• Pimples
• Deep Pimples

The Acne appears wherever there are many oil (sebaceous) glands, mainly on the face, chest, and back. Acne is commonly called as zits. If you understand causes on acne You will be able to take care of your acne, or at least you will have confidence that you can manage to cure it.

Bacteria.
which live in everybody's skin but generally mind their own business, feast on this oil, grow a lot, and cause the surrounding tissues to become inflamed.

If the inflammation is right near the surface, you get a Pustule;
if it's a little deeper than a Pustule then it is a Pimple;
If the inflammation deeper than the pimple then it's a deep Pimple.
If the oil breaks though to the surface, the result is a Whitehead
If the whitehead is oxidized then (oxygen acted on it in the air), the oil changes its color from white to black, and the result is a Blackhead.
And if nothing happens, here is the normal screen.

These factors do not cause acne.
Inheritance.
Except for very severe acne, one will not have the acne problem the way their parents had it. Besides, some degree of acne is almost universal.
Food.
People say to avoid pizza, chocolate, oily and fried foods. While these foods may not be good for your health, good news is they will not make acne worse.
Dirt.
Oil is a natural production of the oil glands, though some people are naturally oilier than others. "Blackheads" are not dirt but oxidized white head. Sweat that you get from exercise also doesn't cause acne. On the other hand, if you wash your skin again and again it can dry and irritate the skin.
Stress: Some people (i hope you are not one of them) get so upset because of their pimples that they pick at them this make them last longer (this is the only indirect reason that can make acne worse). Stress, a direct role in causing acne.
Hormones
Some women have acne cyclically, but most women (and all the men, of course) do not.

The best and most difficult way is : prevention is better than cure, it is better that you do not let it happen, but how can you stop it if you don't know when it is going to attack you. LOL.

But if you had it, and it is not bothering you. just let it as its (recommended), but women , at least will not accept this. If you think it is coming up again and again, you better treat it.
don't go after my recommendations if a single pimple decides to pops up the week before your promotion or wedding.

Three things you can do (medically) to reduce acne are (1) unclog pores; (2) kill bacteria; and (3) minimize oil.

Opening Pores
If you open your skin pores, you can reduce acne. Simple!.
Mild cleansers: Washing once, twice or even thrice a day with a mild cleansing liquid or bar will keep the skin clean and minimize sensitivity and irritation.
Exfoliating cleansers: A variety of mild scrubs, exfoliants should be used. These products contain fine granules and salicylic acid in a concentration that makes it a very mild peeling agent. This removes the outer layer of the skin, and thus open pores.
Killing Bacteria
Antibacterial cleansers: The most popular ingredient in antibacterial cleansers is benzoyl peroxide.
E external/Topical applications: These products come in the form of creams, gels and lotions, which are applied to the affected area. these may include benzoyl peroxide, sulfur that kill bacteria.
Reducing Oil
Oil is normal. You can not stop your oil glands to produce oil. What you can do is to eliminate oil on the surface of the skin.
You can use a gentle toner to wipe the oil. Products that contain glycolic acid or one of the other alpha-hydroxy acids are also mildly helpful in clearing the skin because these chemical peel away superficial layer of the skin.
Antibacterial pads that contain benzoyl peroxide also help you to wipe away oil.