I agree with Meeker. Stretch marks are caused by a rapid stretching of the skin, usually associated with rapid weight gain. THe growth of skin can't keep up with the underlying growth of body tissue, the tissue breaks down and scar tissue is formed. Many times you won't notice them until you lose weight because they become more dense, if you will, once the skin begins to shrink again. This often happens during pregnancy. WOmen may not notice they have stretch marks until they deliver the baby. Fortunately, even though they may look dark or bright pink at first, they often fade with time. Vitamin E can help the appearance of the scar tissue but once there, they are permanent (barring surgery of course).