This is a continuous process that begins in our 20's when skin cell production slows down. Premature aging begins in the 20's and may not show up until decades later. Possibly why so many young adults continue to ignore the warnings about sun damage to their skin. At this stage, collagen production begins to lessen and elastin begins to be less stretchy. Dead skin cell turnover is not as fast nor do they shed as easily.
Signs of this natural aging process might be :
Hereditary factors determine how and when the ageing process begins and how fast it proceeds. Any one of these symptoms of ageing skin might occur first followed by others at any time. Some may show in people as early as their 20's while others may not show until 40 years of age.