Stretch marks are indented streaks or lines that sit slightly below the surrounding skin’s surface. They typically measure several centimeters long and 1 to 10 millimeters wide, running in parallel bands across areas where the skin has been stretched rapidly. Their appearance changes significantly over time, shifting in both color and texture as they mature.
What New Stretch Marks Look Like
Fresh stretch marks are colorful. On lighter skin, they appear bright pink or red. On deeper skin tones, they often show up as dark brown, purplish, or gray. This early stage is when stretch marks are most noticeable because the color contrasts sharply with surrounding skin. The surface may feel slightly raised or puffy at first, as the deeper layers of skin are actively inflamed and swollen.
At this point, the marks look like smooth, slightly shiny streaks. They can feel different from normal skin when you run your finger across them, with a faintly ridged or soft texture. Some people describe a mild itching or tenderness in the area as the marks are forming, though they’re not painful.
How They Change Over Time
Over months, stretch marks gradually lose their color and settle into a paler, more faded version of themselves. They become flatter, thinner, and take on a whitish or silvery tone that looks scar-like. On darker skin, mature marks can appear starkly white or may remain somewhat darker than the surrounding skin, depending on the individual. This fading process generally takes 6 to 12 months, though it can stretch closer to 18 months or longer.
The texture also shifts as they age. Mature stretch marks feel softer and thinner than the skin around them, with a slight indentation you can see and feel. The surface develops a fine, crinkled quality. Underneath, the structural fibers that normally keep skin elastic have snapped and curled into tangled, disorganized patterns, which is why the skin in that area never fully bounces back to its original thickness.
Where They Typically Appear
Stretch marks follow the direction of skin tension, so they tend to run perpendicular to the way the skin was stretched. The most common locations are:
- Abdomen: the single most common site, especially during pregnancy (about 70% of pregnancy-related stretch marks appear here)
- Hips and thighs: common during puberty growth spurts and weight gain
- Breasts: frequent during pregnancy and adolescent development
- Buttocks: often linked to rapid weight changes
- Upper arms and shoulders: seen in people who gain muscle mass quickly
On the abdomen, they usually fan out from the belly button in arcing lines. On the hips and thighs, they tend to run vertically or at a slight diagonal. On the breasts, they typically radiate outward from the center.
Appearance on Different Skin Tones
Skin tone significantly affects how stretch marks look at every stage. People with deeper skin tones face a higher risk of darkening around the marks, where the skin produces extra pigment in response to the stretching injury. This can make the marks more visible and harder to conceal than on lighter skin, where the marks tend to start pink and fade to white.
The mature phase can also look quite different. On fair skin, old stretch marks blend in somewhat because the silvery-white color isn’t drastically different from the surrounding tone. On darker skin, the contrast between a pale, depigmented streak and the surrounding complexion can remain quite pronounced, even years later. This is worth knowing because some cosmetic treatments designed to improve stretch marks, particularly laser procedures, can actually worsen pigmentation changes in deeper skin tones.
When Stretch Marks Signal Something Else
Most stretch marks are completely harmless and result from pregnancy, growth spurts, or weight fluctuation. About 56% of people develop them during a first pregnancy alone. But certain characteristics can point to an underlying hormonal condition.
Stretch marks associated with excess cortisol production (a condition called Cushing’s syndrome) look distinctly different from ordinary ones. They are thick, deep purple, and wider than 1 centimeter, which is noticeably broader than typical marks. The intense reddish-purple color comes from blood vessels in the deeper skin layers showing through unusually thin, fragile skin. These marks often appear on the abdomen, thighs, and upper arms, and they tend to be accompanied by other symptoms like unexplained weight gain around the midsection, easy bruising, and muscle weakness.
If your stretch marks appeared without an obvious trigger like pregnancy, growth, or weight change, or if they’re unusually wide and deeply colored, that pattern is worth mentioning to a doctor.
Why They Look the Way They Do
The visual changes in stretch marks trace directly to what’s happening beneath the surface. When skin stretches faster than it can adapt, the collagen and elastic fibers in the deeper layer tear apart. In the early phase, the body sends an inflammatory response to the area, bringing blood flow that creates the red or purple color. The swelling from this inflammation is what gives new marks their slightly raised feel.
As the inflammation fades, those broken fibers reorganize into thin, tightly packed bundles that lie flat and parallel to the skin’s surface, much like scar tissue. The elastic fibers, which normally sit in thick, evenly spaced arrangements, end up curled and tangled in random directions. This structural damage is permanent, which is why stretch marks become thinner and indent below the surrounding skin rather than rebuilding to their original thickness. The loss of pigment-producing cells in the damaged area is what gives mature marks their pale, washed-out appearance on lighter skin.