This is probably the most frustrating misconception about stretch marks. Stretch marks don’t only result from pregnancy, and they’re not even exclusive to women. According to Mayo Clinic, what causes stretch marks, besides pregnancy, is weight gain, medication use (mainly steroids), and certain diseases (like Cushing’s Syndrome and adrenal gland diseases).
Most commonly, anytime you’re experiencing rapid growth where your skin can’t keep up, stretch marks will be a possibility. That includes everything from going from an A cup to a D cup during puberty, gaining 20 pounds freshman year of college, or being pregnant with twins. Stretch marks can also result from muscle growth, because that counts as weight gain, too. If you’ve ever checked out the hardcore lifters at the gym, you may notice some of them have stretch marks on their biceps or calves. Stretch marks are not exclusive to having a bun in the oven.