Stretch marks are the result of the breakage of the elastic fibers of the skin. When the skin is stretched the fibers with less elasticity are broken creating marks that we call stretch marks. At first the striae are pinkish then reddish and finally white. Stretch marks are basically the reflection of the tearing of the skin. The skin when stretching does not hurt, sometimes it can produce a sensation of light ardor. Stretch marks are more common in the abdomen, but also appear on the thighs, hips, bust and arms.