Stretch marks can have causes that aren’t due to underlying disease. Examples include pregnancy, weight gain in obesity, growth spurts in teenagers, medication side effects or a rapid increase in muscle size through weightlifting.
A stretch mark is a type of scar that develops when our skin stretches or shrinks quickly. The abrupt change causes the collagen and elastin, which support our skin, to rupture. As the skin heals, stretch marks may appear.
Not everyone develops these narrow bands on their skin. Fluctuating hormone levels seem to play a role. You may also have a higher risk if people in your family get stretch marks.
Stretch marks (striae) are indented streaks that appear on the abdomen, breasts, hips, buttocks or other places on the body. They’re common in pregnant women, especially during the last trimester. Stretch marks aren’t painful or harmful, but some people don’t like the way they make their skin look.