Stretch marks:

Stretch marks or striae, as they are called in dermatology, are a form of scarring on the skin with an off-color hue. They are caused by tearing of the dermis, and over time can diminish but not disappear completely. Stretch marks are the result of the rapid stretching of the skin associated with rapid growth (common in puberty) or weight gain (e.g. pregnancy and/or muscle building) that overcomes the dermis's elasticity. Although stretch marks are generally associated with pregnancy they can also develop during rapid muscle growth. Medical terminology for these kinds of markings includes striae atrophicae, vergetures, stria distensae, striae cutis distensae, or simply striae.

Stretch marks can appear anywhere on the body, but are most likely to appear in places where larger amounts of fat are stored. Most common places are the abdomen (especially near the belly-button), breasts, upper arms, underarms, thighs (both inner and outer), hips, and buttocks. They pose no health risk in and of themselves, and do not compromise the body's ability to function normally and repair itself. Treatable with: Dermaroller