Stretch marks are tears in the skin that usually first appear among girls during puberty. They can also occur during pregnancy and menopause and are found among men and women who have gained a lot of weight or who have rapidly gained bulky muscles. Due to the altered hormone balance in the body and the resulting growth spurt, weak subcutaneous tissue is overstretched.
This overstretching can cause tears in the tissue and subsequent irreparable scar formation. The areas of the body that are most affected by stretch marks are the bust, stomach, buttocks, thighs and hips.