A: Acne can be caused by excess sebum oil and clogged pores. Doctors aren’t sure why some people get acne and others do not, but some research suggests that hormone levels may play a role. [see Sources 1 and 2 in Source List below]

Acne is most common in young adults with increasing hormone levels, and about 80 percent of people will have at least one [acne] outbreak before age 30. It is less common in older adults, who tend to have steadier hormone levels. Since stress can affect hormones, it may also play a role in the development of acne, but so far, there is no definitive evidence that factors such as stress, diet, or light makeup have any links with acne. If you have acne, wash gently with a mild cleanser no more than twice a day; and avoid hard scrubbing, exfoliating, and touching the affected areas.

A: UV exposure and hormonal changes are two causes of dark spots. Avoiding the sun and wearing sunscreen can prevent new dark spots from forming, while exfoliating regularly or using prescription medications may help treat the existing spots you already have. Certain dark spot correctors or moisturizers may also make a difference over time. Remember to choose the products that are formulated for your skin type.