Stretch Marks in Teens: The Growth Spurt Explains It

Stretch marks in adolescence are ordinary and mostly misread. Parents assume weight; the usual driver is height. During the pubertal growth spurt the body lengthens faster than the dermis can remodel, connective tissue fails along lines of tension, and pale or purple bands appear on a teenager who has gained little or no fat. StatPearls reports prevalence in adolescence anywhere from 6% to 86% — a range that says more about how hard different studies looked than about how common this is.

Height, not weight, is usually the cause

Physiologic striae atrophicae of adolescence occur mainly in healthy, non-obese teenagers, in association with the growth spurt. Growth of several inches over a year or two is a mechanical event, and the skin is the tissue that has to absorb it. Adding weight gain or a training program on top of that stacks a second stretch onto the first, which is why the heaviest crop tends to land on teenagers who grew fast and changed shape in the same window.

Where they land, and why boys and girls differ

The distribution splits along how puberty redistributes the body. In boys, the outer thighs and the lumbosacral region — the lower back — are the classic sites, with shoulders and upper arms joining in when weight training is involved. In girls, the thighs, buttocks and breasts dominate. Two consequences follow. First, a boy’s marks are often on his back, where he cannot see them and nobody mentions them until a beach day. Second, the sites in girls overlap with the ones adult women associate with weight, which invites a wrong explanation and an unnecessary diet.

Weight training adds a second stretch

Rapid muscle hypertrophy is a recognized cause in its own right, listed by StatPearls next to pregnancy and puberty. A teenager who adds substantial size to shoulders, chest and arms over one season is doing to the skin exactly what the growth spurt does — faster, and in a smaller area. The mechanism is described in more detail in stretch marks causes. Gradual progression is the only lever, and it is a modest one.

When someone should look closer

Most adolescent striae need no evaluation at all. These do:

• Wide, purple, spreading bands rather than fine lines
• Marks appearing without a growth spurt, weight change or training block
• A history of potent topical steroids, oral steroids or high-dose inhaled steroids
• Striae plus trunk weight gain, slowed height growth, easy bruising or high blood pressure
• Striae in a young child, which is not part of normal development

The last three raise the question of Cushing syndrome or steroid exposure, and both are worth a pediatrician’s attention rather than a cosmetic conversation.

The part that hurts is not the skin

A 2021 study in Turkish Archives of Pediatrics looked at quality of life in 50 children and adolescents aged 9 to 16 with striae distensae, using a dermatology life-quality index rather than a skin score — because the impact of this condition is social, not medical. Striae are benign, asymptomatic and permanent, and a teenager’s real question is usually about the locker room, not the dermis. Two things help: knowing that most classmates in the same growth window have them somewhere, and knowing that the color fades a great deal on its own. What that fade looks like is covered in red vs white stretch marks.

What actually helps at this age

Moisturizer is comfortable and does no harm; it is not prevention, and the evidence behind prevention claims generally is examined in how to prevent stretch marks. Gradual change — in weight, in training volume — is the one real lever. And if the marks matter enough to treat, early is the only moment worth acting on.

This content is informational and does not replace medical consultation, diagnosis, or treatment.