Not all scars look alike
People often talk about “a scar” as if it were one thing. In practice, clinicians describe several recognizable patterns, and the same injury can lead to different patterns in different people. The names below are widely used, though the boundaries between them are not always sharp, and a single scar can show features of more than one.
The commonly described types
Flat or normal scars. Many scars mature into a pale or slightly pink line that sits level with the surrounding skin and softens over many months. This is the most common outcome for a clean, well-healed wound, and it is the one most people hope for. Even these scars typically look and feel a little different from the surrounding skin.
Atrophic scars. These are sunken or pitted. They happen when the skin does not rebuild enough underlying tissue, leaving a depression. Acne scars are a familiar example, and so are marks left by chickenpox.
Hypertrophic scars. These are raised, often red and firm, and stay within the borders of the original wound. They can develop when the body produces too much collagen during repair. They often improve gradually over time, though that can take a long period.
Keloid scars. These are also raised, but they grow beyond the edges of the original wound and may keep enlarging. They do not typically fade by themselves in the way many hypertrophic scars do. Keloids are discussed at length under keloid scarring, so this article only notes the difference: staying inside the wound edge versus spreading past it.
Contracture scars. These form when scar tissue tightens as it matures, pulling the skin and sometimes limiting movement. They are most often associated with larger or deeper injuries, such as burns, and especially where skin crosses a joint.
Stretch-related marks. Stretch marks are a different kind of change within the dermis rather than the result of an open wound. They have their own explanation under stretch marks.
What is reasonably well understood
Researchers have a good grasp of the general picture.
- Scars arise when an injury reaches the dermis, the thicker layer beneath the surface, and the body fills the gap with collagen-rich repair tissue.
- Raised scars are linked to overactive repair, with extra collagen and prolonged inflammation.
- Sunken scars are linked to loss of tissue or insufficient rebuilding.
- Tension matters. Wounds on parts of the body that move or stretch often scar more visibly than wounds on still areas.
- Infection, repeated irritation and slow closure are widely associated with worse scarring.
What is less certain
Several important questions do not have simple answers, and it is better to say so than to guess.
Why some people form raised scars and others do not. A tendency toward keloids and thick scars appears to run in some families, and it is more often reported in people with darker skin tones. The exact biological reasons are not fully settled, and having a risk factor does not mean a person will definitely form such a scar.
Why location matters so much. Areas like the chest, shoulders and upper back are often mentioned as more prone to raised scarring, while others rarely produce them. Explanations involving skin tension and local biology exist, but they are not a complete account.
Why results differ in identical wounds. Two people with similar wounds can end up with very different scars. Doctors can describe risk factors, but they usually cannot forecast a particular person’s outcome precisely.
Which treatments work best. Clinicians use a range of approaches for troublesome scars, and the evidence for different options varies in strength. Responses differ between individuals, and some scars return after treatment. This is a matter for a doctor or dermatologist rather than something to improvise. If you are curious about what is generally possible, scar revision in general terms outlines the landscape.
Factors that influence which type develops
- Genetics and family history. Often the strongest hint about how someone scars.
- Skin tone. Color changes after injury, such as darker or lighter patches, can differ across skin tones, as discussed under skin tone.
- Age. Younger skin often produces a more vigorous repair response, which may relate to raised scars, while older skin may heal more slowly.
- Wound characteristics. Depth, width, location, and how much the wound is pulled during movement.
- Complications. Infection, foreign material in the wound and prolonged inflammation.
- Underlying conditions and medications. These can affect repair in ways that a doctor can assess.
Why this matters for body art
Anything that breaks the skin deeply enough to reach the dermis carries some scarring risk. For most people, a procedure carried out by licensed professionals under clean conditions heals without a significant scar. But some people have a known history of thick or raised scarring, and for them the risk is different. Anyone with a personal or family history of keloids, or with health conditions that affect healing, should speak to a doctor before any procedure that would injure the skin, and tell the professional about that history during a medical consultation or booking conversation. Piercing rejection and similar complications are also linked to how the skin responds, and not all of them are within the control of the person or the professional.
Realistic expectations
Because a scar keeps changing for many months, early appearance is not a final verdict. Redness, firmness and thickness often reduce with time. On the other hand, nobody should be told that a scar will vanish completely, since in most cases a scar of some sort remains, even if it becomes faint.
If a scar is growing, painful, itchy in a persistent way, restricting movement or distressing, it is reasonable to see a doctor. Treatment decisions depend on the scar type, and identifying that type correctly is the first step. Self-diagnosis from photographs can be misleading, so a professional exam is more reliable than comparing your skin with images online.