Photoaging/photodamage may take place over time or rapidly, as in when you suffer a sunburn. Photoaging and photodamage are terms used interchangeably to describe changes in the appearance and function of the skin caused by repeated sun exposure rather than by the passage of time (the latter is called intrinsic or chronologic aging). Overwhelming evidence indicates that sun exposure and other sources of ultraviolet (UV) radiation play the major role in causing the undesirable skin changes of fine and coarse wrinkles, roughness, loose skin, brown spots, pre-cancerous growths called actinic keratoses, leathery texture/coarseness, and small red veins.  Cigarette smoking is the only other environmental factor that has been related to the development of changes in the skin associated with aging.