Stretch marks often appear without warning, leaving many people wondering why their skin develops these peculiar marks. In reality, these marks are not simply due to stretching of the skin, but result from a complex combination of hormonal factors and changes in the very structure of the dermis. In this article, we’ll explore the real causes of stretch marks and understand why some people are more prone to them than others.
Introduction to stretch marks
Stretch marks affect the vast majority of women and many men throughout their lives. These scar-like marks form when the skin undergoes significant changes. Although often associated with pregnancy, they can appear at different times in life, notably during puberty or when there are significant weight variations.
Hormonal and physiological factors in stretch marks
Hormones play a major role in the appearance of stretch marks. Cortisol, the stress hormone, is often to blame. When produced in excess, it prevents the skin from producing collagen. Without sufficient collagen, the skin loses its elasticity.
Puberty is a particularly good time for stretch marks. Hormonal changes upset the body, and the skin is not spared. In teenage girls, stretch marks appear on average around the age of 14.
During pregnancy, hormones are also responsible. Between 50 and 70% of women pregnant with their first child develop stretch marks, especially from the sixth month onwards. The risk increases with :
- High body mass index in early pregnancy
- Significant weight gain (over 15 kg)
- A baby weighing over 3.5 kg
Athletes are not spared. In bodybuilding, for example, rapid muscle mass gain can lead to stretch marks. The same applies to any rapid change in volume, whether weight gain or loss.
Some people are naturally more at risk. If you have fair or reddish skin, or if your skin is particularly thin, you’re more likely to develop stretch marks. This is also the case if your skin naturally produces less collagen and elastin.
But beyond hormones and individual predisposition, another key factor comes into play: skin stretching. This phenomenon, often linked to rapid changes in the body, explains why some populations are more exposed than others.
The role of hormonal changes
Hormones are largely responsible for the appearance of stretch marks. During pregnancy, the body undergoes a veritable hormonal revolution. Hormone levels soar, and this has a direct impact on the skin. Puberty is another period when these changes are particularly marked.
These hormonal upheavals have a very concrete effect: they directly modify the structure of this protein in the skin. Collagen is the protein that gives our skin its suppleness and resistance. When hormones get involved, they can disrupt its production and organization.
Estrogen and progesterone play a major role in these transformations. These hormones, whose levels increase considerably during pregnancy, modify the structure and elasticity of the skin. In particular, estrogen influences tissue hydration, while progesterone can affect the skin’s ability to adapt to changes in volume.
Skin stretching and at-risk populations
Stretch marks appear when the skin stretches too quickly. It’s simple: our skin is elastic, but it has its limits. When we force it to stretch faster than it can adapt, it cracks deep down.
Some people are more likely than others to develop these little marks. Teenagers, for example, can develop them as they grow. This is particularly true for girls, whose bodies change rapidly.
Significant weight variations are also a major cause. Whether it’s a rapid gain or loss, the skin doesn’t have time to adapt. That’s why people on drastic diets or who are overweight can be affected.
Athletes are not spared either. Bodybuilders and weightlifters can see stretch marks appear when their muscles grow too fast. The same applies to people who have undergone certain operations, such as breast augmentation.
These marks have their own areas of predilection: the stomach, thighs, breasts, hips and buttocks are the most affected. For men, the lower back is also a sensitive area.
On each of these areas, stretch marks can take on different appearances depending on their location and stage of evolution. These variations in appearance give us a better understanding of how they develop and evolve over time.
Find out more about stretch marksIt’s important to note that rapid stretching of the skin profoundly disrupts its structure.
Rapid skin stretching
Rapid stretching of the skin profoundly disrupts its structure. When skin is forced to stretch too quickly, the collagen fibers that give it its elasticity tear. It’s like a piece of fabric that’s suddenly stretched: it ends up cracking.
Your skin type also plays a role. Thin, fair skins are more sensitive to these brutal stretches. They tend to mark more easily, simply because they are naturally more fragile.
Pregnant women and growing adolescents
Pregnant women and teenagers are the most affected by stretch marks. It’s logical: their bodies change rapidly. During pregnancy, stretch marks appear on almost 90% of women, mainly on the stomach and breasts. For teenagers, it’s a different story: the marks form mainly on the thighs, buttocks and lower back.
In teenagers, it’s growth that’s to blame. Girls are more affected than boys: 70% versus 40%. The good news? Puberty stretch marks often fade over time.
One important thing to know: anxiety about these physical changes can make the situation worse. So it’s worth bearing in mind that this is a natural phenomenon. To limit their appearance, opt for a balanced diet, rich in vitamins A, C and E.
Types of stretch marks
Not all stretch marks are the same. In fact, they evolve and change appearance over time. There are two main types: red streaks and white stretch marks.
Red stretch marks are the newcomers. They first appear with a red or purplish color, rather like a small inflammation. This is normal: at this stage, there’s still a great deal of activity under the skin. These stretch marks are more receptive to various treatments, so this is the best time to act if you want to reduce them.
Over time, these red marks fade and gradually turn white. These are known as mature stretch marks. They take on a lighter, pearly hue than the surrounding skin. These stretch marks are more difficult to treat, as the skin has already completed its healing process.
It’s useful to know how to recognize both types. If you notice red stretch marks, now is the ideal time to start treatment if you wish. For white stretch marks, even if they are more stubborn, certain solutions can help improve their appearance.
Red stretch marks (recent)
Red stretch marks are the easiest to treat, so it’s important to spot them early. They appear as reddish or purplish lines on the skin, and can sometimes be sensitive to the touch. They are called “immature” because they are still in the development phase.
These marks appear mainly on the stomach, thighs, chest and buttocks. The good news? It’s at this stage that treatments are most effective. Studies show that regular application of specific skin care products can really make a difference: in most cases, the color fades.
For effective action, opt for creams containing Aloe vera, vitamin A or natural extracts such as Centella Asiatica. Apply these twice a day for at least two months. More advanced techniques such as laser or microneedling can also be considered, but talk to a professional first.
White stretch marks (old)
White stretch marks are permanent scars. Over time, red stretch marks lose their color and become lighter than the surrounding skin. Their texture also changes: they appear slightly indented, like small pearly furrows.
Even if these marks are permanent, there are solutions to improve their appearance. The most effective treatments are carried out by professionals:
- The CO2 or erbium laser, which renews skin cells
- Radiofrequency to stimulate collagen production
- Microneedling to help regenerate the skin
These techniques require several sessions, with results appearing gradually. They are most effective when used in combination. However, be patient: white stretch marks are more difficult to treat than red ones, as the scar tissue is already well established.
