Stretch marks are a type of scar that forms when the skin stretches or shrinks rapidly. This sudden change causes the collagen and elastin, which support the skin, to tear. As the skin heals, stretch marks may appear.

Not everyone develops these narrow bands on their skin, as fluctuating hormone levels play a significant role. Your risk is higher if you have a family history of stretch marks.

You are most likely to develop stretch marks during the following times:

- Growth spurts during puberty
- Pregnancy
- Rapid weight loss or gain
- Weight training with rapid muscle growth