When the skin is injured, it goes through a healing process in three main stages. First, inflammation occurs as blood vessels constrict and immune cells rush to protect against infection. Second, fibroblast cells produce collagen to rebuild the damaged area. Unlike the smooth, organized structure of healthy skin, scar tissue is made of thicker collagen laid down in a less structured way. Finally, the remodeling phase strengthens the tissue over weeks or months.

The appearance of a scar depends on many factors, such as the depth of the wound, location, age, skin type, and genetics. Some scars remain small and faint, while others are more prominent and long-lasting.

Scars can result from almost any injury that extends into the dermis. Common causes include cuts, surgical incisions, burns, acne, chickenpox, or repeated scratching. The severity and depth of the wound play a major role in whether a scar develops. Deeper injuries are more likely to leave visible marks.

Even minor injuries can sometimes scar, depending on how the body heals. For example, acne lesions may leave behind sunken marks, while surgical incisions often leave linear scars. Burns can result in more complex scars, such as contractures, which tighten skin and may limit movement.

There are several types of scars, each with unique characteristics:

• Atrophic scars: Sunken or pitted scars, often caused by acne or chickenpox.
• Hypertrophic scars: Raised scars that stay within the boundary of the wound.
• Keloid scars: Thick, raised scars that grow beyond the wound area. These may be itchy or painful.
• Contracture scars: Common after burns, these scars cause the skin to tighten, which may restrict movement.
• Stretch marks (striae): A type of scarring caused by rapid stretching of the skin during pregnancy or weight gain.

Each type can look and feel different, and some are more challenging to manage than others.

Nearly everyone develops scars at some point. A childhood scrape, acne outbreak, or a surgical incision often leaves behind lasting marks. Some scars fade over time and become barely noticeable, while others remain prominent. Acne scars affect millions of people, and surgical scars are routine for anyone who has undergone an operation. Keloid scars are less common, but they can significantly impact those who are prone to them.

Scars are part of life’s healing process. While they are extremely common, how they form and how noticeable they become varies widely from person to person.

Scars are generally easy to identify. They may be a different color than surrounding skin, either lighter, darker, or reddish. Some scars are raised above the skin surface, while others are sunken or depressed. They can feel smooth, rough, or shiny. In the months after they form, scars may be itchy, tender, or even painful.

Although scars are usually harmless, they may cause emotional distress if highly visible. Some types, like contracture scars, may also cause physical discomfort or limit movement.

Scars rarely disappear completely on their own. Most will fade and become less noticeable over time, but they typically do not vanish entirely. A surgical scar, for example, may start red and raised but gradually flatten and lighten over one to two years. However, some scars, such as keloids, may grow larger or thicker instead of fading.

The natural course of a scar depends on the type, location, and individual healing process. While scars may soften or become less visible, they generally remain to some degree.

Leaving a scar untreated is not harmful to your overall health, but it may lead to other issues. Visible scars can cause cosmetic concerns and affect self-esteem. Some scars are physically uncomfortable, becoming itchy, tender, or even painful. Contracture scars, especially after burns, may restrict movement around joints.

Emotionally, acne scars or large visible marks may contribute to low confidence or anxiety. While treatment is not always necessary, many people choose to address scars for personal or functional reasons.

Everyone can develop scars, but some people are more prone to prominent ones. People with darker skin tones are more likely to develop hypertrophic or keloid scars. Younger individuals may produce more collagen, leading to thicker scars. Deep wounds or injuries raise the likelihood of noticeable scarring. Genetics also play a role, especially in keloid formation.

People with inflammatory acne are at particular risk, since untreated breakouts can leave behind permanent marks.

Not all scars can be avoided, but taking care of wounds can reduce the risk. Keeping healing skin clean and moisturized, protecting it from infection, and avoiding scratching or picking can make scars less noticeable. Covering new scars from the sun is important because ultraviolet rays can darken them permanently.

Even with careful care, some scars are unavoidable, especially after deeper injuries or surgery.