It is good to take care of your skin and follow a thorough skin care regimen on a daily basis. Those with oily skin need to be more careful. Having oily skin can be hereditary, or one may acquire it over time. Lifestyle, hormonal imbalance and hormonal changes related to birth control pills, menstrual periods and pregnancy can trigger acne. Use of too many cosmetics and hot or humid weather are some of the factors that may be held responsible for oily skin.