CAUSES OF STRETCH MARKS
When the skin stretches in an unusual way, it loses its elasticity. As a result, the topmost layer of skin shows stretch marks because the second skin layer, or the skin beneath the top-skin-layer, breaks down. In short, these marks are caused because of loss of elastic fiber and collagen in the second, deeper layer of our skin. Collagen is a protein rich compound that is responsible for rejuvenating and repairing the human skin. Stretch marks can usually be seen on thighs, abdomen, arms, knees and waist.