The skin has a range of needs that depend on the skin type, the season of the year and your age. Young skin tends to be firm but may suffer from acne. Pimples especially appear during puberty when the secretion of sebum or skin oil increases. The increased sebum production results from hormonal imbalance. After the age of 25, some skin renewal processes start to slow down. As a result, the skin is less firm, the first fine lines start to appear and the complexion becomes uneven. The rate of the skin renewal processes is affected by your genes, as well as your lifestyle and skin care habits.