Complete Healthcare Team
Quick answer: Stretch marks are narrow, streaky lines that form when skin stretches faster than it can adapt, which damages the collagen and elastin fibers in the dermis, the skin’s middle layer. They come from rapid growth, pregnancy, weight gain or fast muscle building, and they are harmless. New marks are often red, pink or purple and slowly fade to paler lines.
Stretch marks aren’t a sign that you did anything wrong, and they aren’t really on the surface of your skin at all. They form deeper down, in the middle layer of the skin, when it stretches faster than it can keep up with. That’s why they show up during the most normal and healthy of circumstances, like pregnancy, growth spurts, and building muscle, and why creams applied to the surface can only do so much. Understanding what’s actually happening in your skin makes them far less mysterious.
Stretch marks are extremely common, they’re harmless, and they happen to most people at some point. The gynecology team at Complete Healthcare talks with patients about them often, especially during and after pregnancy, and this guide explains how they form, why they show up where they do, and what actually helps.
What Are Stretch Marks?
Stretch marks, known medically as striae, are a form of scarring in the dermis, the middle layer of your skin. When skin is stretched quickly, the collagen and elastin fibers that give it strength and flexibility get damaged and can tear. As the area heals, it forms the narrow, streaky lines we recognize as stretch marks.
The key thing to understand is that they aren’t a surface problem. They originate below the outer layer of skin, which is exactly why surface treatments have limits, and why they behave like scars rather than like dryness or discoloration you can simply wash or buff away.
What Do Stretch Marks Look Like?
Stretch marks look like narrow bands or streaks, often running side by side, on the belly, breasts, hips, buttocks, thighs or upper arms. How they look depends on how old they are and on your skin tone:
- New marks can be red, purple, pink, reddish-brown or dark brown, depending on your skin color. On brown and darker skin they are more likely to look reddish-brown or dark brown than pink. They may feel slightly raised and itchy.
- Over time the color fades and the marks sink a little below the surface, so a mature stretch mark often feels like a slight dip when you run a finger over it.
- Older marks are usually lighter than the skin around them: white, silvery or close to your skin tone.
Stretch marks are not painful. A mark that hurts, bleeds or changes quickly in a way that does not fit this pattern is something to show a provider.
How Stretch Marks Actually Form
The mechanism is essentially rapid stretch outpacing your skin’s ability to adapt. When your body changes shape faster than the skin can grow with it, the supportive fibers in the dermis break, and the healing of those tiny tears creates a stretch mark. This is why stretch marks tend to run perpendicular to the direction the skin is being stretched.
A few factors influence who gets them and how much:
- Speed of change. Rapid weight gain, growth, or muscle building is more likely to cause stretch marks than gradual change, because slow stretching gives skin time to adapt.
- Hormones. Cortisol, a stress hormone, can weaken the skin’s collagen and elastin, which is part of why stretch marks appear during hormonally active periods.
- Genetics. If your parents had stretch marks, you’re more likely to as well, since your genes influence how much collagen and elastin your skin has and how it responds to stretching.
- Age and skin qualities. Skin’s elasticity changes over time, which affects how it handles stretch.
None of these are things you did wrong. They’re mostly biology, which is worth remembering if stretch marks bother you.
Other Causes of Stretch Marks
Beyond growth, pregnancy and weight gain, stretch marks can also come from:
- Rapid weight loss, since skin that shrinks quickly can tear too
- Long-term use of corticosteroid medicines, including steroid creams applied to the skin
- Using anabolic steroids while building muscle
- Breast enlargement surgery
- Certain medical conditions, including Cushing syndrome and Marfan syndrome
If you use a steroid medicine and notice new stretch marks, tell the provider who prescribed it rather than stopping it on your own.
The Two Stages: Red Marks to Silver Lines
Stretch marks change over time, and knowing the stages helps set expectations. Fresh stretch marks, called striae rubrae, appear as raised red, pink, or purplish lines. The color comes from blood vessels visible through the small tears in the dermis, and these newer marks may feel slightly itchy.
Over months to years, they mature into striae albae, which are flatter, silvery-white or skin-toned lines. This matters for treatment, because newer red marks tend to respond better to treatment than older white ones, which is why acting sooner, if you want to address them, generally works better.
Why Stretch Marks Show Up Where They Do
Stretch marks appear wherever skin stretches rapidly, which is why certain areas are especially common.
Pregnancy stretch marks. Known as striae gravidarum, these are among the most common, affecting a large majority of pregnant women, with estimates often cited between 50 and 90 percent. They usually appear in the second and third trimesters as the abdomen expands, and they’re driven by both the mechanical stretch of a growing belly and pregnancy hormones like cortisol and relaxin that affect the skin’s collagen. Beyond the belly, they frequently show up on the breasts and thighs during pregnancy.
Stretch marks on the breasts. The breasts commonly develop stretch marks during pregnancy, puberty, and periods of rapid size change, since the skin there stretches as breast tissue grows. This is completely normal and happens to many people.
Stretch marks on the thighs. The thighs are another very common location, and they can appear from weight gain, muscle building, growth spurts during puberty, and pregnancy. On the thighs, stretch marks often start as pink or purple streaks before fading to lighter lines.
Other common areas include the hips, buttocks, abdomen outside of pregnancy, and, in people building muscle quickly, the shoulders and upper arms.
Common Questions About Stretch Marks
Can stretch marks be prevented?
Honestly, not reliably. Because genetics and hormones play such a large role, no cream or oil is proven to prevent stretch marks entirely, despite many products marketed that way. Keeping skin moisturized and gaining weight gradually where possible may help somewhat, and staying hydrated and well-nourished supports skin health, but if you’re prone to stretch marks, you may get them regardless of what you do. That isn’t a personal failing, it’s biology, and it’s worth approaching yourself with some grace.
Do stretch marks go away on their own?
They usually fade but rarely disappear completely. Over time, red or purple stretch marks typically mature into paler, less noticeable silvery lines, and for many people they become much less visible. They generally don’t vanish entirely, though, since they’re a form of scarring. The good news is that they’re harmless and tend to become far less noticeable than they were at first.
What treatments actually work for stretch marks?
Results are modest and vary, so honesty matters here. Prescription retinoid creams like tretinoin have some evidence for improving the appearance of early, red stretch marks, though they’re not safe to use during pregnancy or breastfeeding. In-office procedures like laser therapy and microneedling can help reduce their appearance for some people, working better on newer marks. No treatment reliably erases stretch marks completely. If reducing their appearance matters to you, a provider can talk through which options fit your situation and skin.
What do stretch marks look like on darker skin?
On brown and darker skin, new stretch marks are often reddish-brown or dark brown rather than pink or red. As they age they usually fade to lines that are lighter than the surrounding skin, and they may feel slightly sunken.
Where do stretch marks come from?
They come from skin stretching or shrinking faster than it can adapt. The supporting collagen and elastin fibers in the middle layer of the skin tear, and the lines are what that damage looks like as it heals. Growth spurts, pregnancy, rapid weight change and fast muscle building are the usual triggers, and genes and hormones affect who gets them.
Are stretch marks ever a sign of a health problem?
Rarely. Almost all stretch marks come from ordinary stretching and are harmless. The exception is wide purple stretch marks that appear along with weight gain in the face and upper body, easy bruising or muscle weakness, which can point to Cushing syndrome and should be checked. Widespread marks can also follow long-term steroid use.
When Stretch Marks Are Worth Mentioning to a Provider
Stretch marks are almost always harmless and don’t require medical attention. That said, a couple of situations are worth a conversation:
- Stretch marks that appear suddenly and widely without an obvious cause like pregnancy, growth, or weight change, which is uncommon but occasionally worth evaluating
- Stretch marks alongside other symptoms such as unusual weight changes, since in rare cases widespread striae can relate to hormonal conditions
- When they bother you and you’d like to understand your options for reducing their appearance
- Stretch marks that cover large areas of your body
- Wide purple stretch marks, about half an inch (1 cm) across or wider, together with weight gain in the face and upper body, a fatty hump between the shoulders, thin skin that bruises easily, or muscle weakness. This combination can be a sign of Cushing syndrome, which is caused by too much of the hormone cortisol, and it should be checked.
- New stretch marks while you are taking a steroid medicine
In our practice, we’re always glad to talk through stretch marks, whether the goal is reassurance or exploring treatment.
A Note on How You See Them
It’s worth saying plainly: stretch marks are a normal part of having a body that changes, and the large majority of people have them somewhere. They carry no health risk at all. Whether you want to treat them or simply understand them, both are completely valid, and neither requires you to feel any particular way about marks that nearly everyone shares.
Talk Through Your Options With Us
If you have questions about stretch marks, whether during pregnancy or any other time, or you’d like to understand what can help reduce their appearance, we’re happy to help. Complete Healthcare offers gynecology care with same-day appointments available across our 11 locations in Central Ohio, including Columbus, Pickerington, Newark, Lancaster, Marion, Marysville, and Delaware. Call us at 614-882-4343 or schedule online to get started.
