Usually, hormones are to blame, but there can be other factors present that can cause acne or make it worse than it needs to be.
Alcohol is one possible culprit. When the body cleanses itself of alcohol it sends it out through the pores of the skin which in turn can become clogged.
Caffeine increases the stress hormones produced by your body and this in turn can affect your acne. Remember that caffeine can also be found in some soft drinks and, in smaller amounts, in chocolate.
A small number of people may be sensitive to dairy products. You could try reducing your intake and see if it helps. Try to use low lactose products or natural yogurt that contains acidophilus. Fatty foods are difficult to digest and can cause eatra oil in the skin. Try to avoid red meat cuts that are fatty.
Acne on the forehead or hairline may be caused by sebum created in the scalp and moving to the forehead. This may be reduced by washing your hair more frequently or using a shampoo designed for oily hair as this can reduce the sebum in the scalp. Hair sprays and gels can also clog pores.
Hats and sweatbands accumulate dirt and bacteria and should be cleaned regularly or avoid wearing them where possible. Both also rub against your forehead causing irritation.
Washing your skin frequently and roughly can actually make your acne worse. Hard rubbing is not recommended, it irritates the skin. Gently wash your face once or twice a day with a mild soap like a glycerin or sorbitol based soap that addresses the ph balance of your skin. Always pat dry skin gently. Use a clean face cloth every time.
You need to be careful when using scrubs. They should not be used more than two or three times a week, or less, follow the directions on the product. Scrubs are good for blackheads but not so good if you have a severe breakout of whiteheads or have serious acne problems.
You hear so often that you should never pop pimples, this is partly because this leaves the way for bacteria to enter the skin. Squeezing ruptures the membranes causing infection and sebum to spread underneath the skin. It can also lead to scarring.
Stress. The theory with this one is that when you are under stress your body creates a number of different hormonal steroids, one of these is cortisol. Some of these hormones can affect the oil production of your body and this oil affects your skin.
As with many things in life, patience is needed when trying new acne treatments. From everything I have read, a reasonable amount of time to see if a product is working for you is eight weeks. It can take this long to really know if a product is being affective.
I started researching acne when my daughter, now a teenager, started breaking out. I have written a short book which you can download for free at my website http://www.instantbooks.com.au