Skin & hair

Keloid or Hypertrophic? The Difference Matters

Save

Pitted vs raised acne scars is one common scar comparison people search for; keloid versus hypertrophic scar is another, and the two categories are often confused because both start as a raised, firm bump after an injury. Telling them apart early changes what treatment is likely to help and how long it should be given a chance to work.

Last updated: July 2026

Talk to a clinician

Gale can help you find a clinician in your state and request a visit.

Find care →

Continue in Claude

Open a chat with this article’s link already in the message, and keep asking questions there. Claude reads the article and its sources; nothing about you is included.

Continue in Claude →

The button opens the Claude desktop app and fills in the message for you to review before sending. No desktop app, or reading on a phone? Copy the prompt and paste it into any AI.

What actually separates a keloid from a hypertrophic scar?

The defining feature is whether the raised tissue stays inside the original wound's borders. A hypertrophic scar is an overproduction of collagen that remains confined to the shape and size of the original cut, burn, or piercing, while a keloid is scar tissue that grows past those borders into surrounding, previously uninjured skin — sometimes doubling or tripling the size of the original injury over months or years. hypertrophic scar describes this contained, self-limiting overgrowth, in contrast to a keloid's tendency to keep spreading. Timing differs too: hypertrophic scars usually appear within weeks of the injury and can start improving within months, while keloids often take longer to become obvious and rarely improve without intervention.

Do they look and feel different day to day?

Both types are typically raised, firm, and can be pink, red, or darker than surrounding skin, which is exactly why the two get confused. Hypertrophic scars tend to be more uniformly raised across the width of the original wound and often become itchy or mildly tender in their first several months before gradually softening. Keloids are more likely to have a smooth, shiny, rubbery surface, can be tender or itchy indefinitely rather than just early on, and — the tell that matters most — extend visibly beyond where the original injury's edges were, which a hypertrophic scar by definition does not do.

Why does a keloid keep growing when a hypertrophic scar doesn't?

The honest answer is that the precise biology isn't fully settled, but keloids are understood to involve a more prolonged and dysregulated wound-healing response, in which fibroblasts (the cells that produce collagen) keep producing it well past the point where healing should have stopped. Genetics plays a real role: keloids run in families and occur more often in people with more richly pigmented skin, while hypertrophic scars show a much weaker genetic pattern and are more closely tied to wound tension, infection, or delayed healing at the injury site. An ear keloid after a piercing is the single most common real-world example of this biology in action, since the ear combines high genetic keloid-proneness in some people with a piercing wound that heals under constant low-grade tension from jewelry. This difference in underlying biology is exactly why the two need different treatment strategies rather than being managed as the same problem at different stages.

Does the difference actually change treatment, or is it mostly academic?

It changes treatment meaningfully. Many hypertrophic scars improve on their own over one to two years with conservative measures — silicone sheeting, pressure, sun protection — and don't need aggressive intervention. Keloid treatment, realistically, usually requires active steps: flattening a keloid with cortisone injections delivered every few weeks is the typical first-line approach, and surgical removal alone tends to backfire, since a keloid-prone person's fresh surgical wound can regrow an even larger keloid than the one that was removed; excision is generally combined with steroid injection, pressure, or another adjunct specifically to blunt that recurrence risk. Choosing the wrong strategy — for instance, waiting patiently for a true keloid to fade the way a hypertrophic scar would — can mean years of unnecessary growth before the right treatment starts.

How does this compare to other kinds of scarring, like acne scars?

It helps to place keloids and hypertrophic scars against a familiar reference point: pitted vs raised acne scars. Acne scarring runs in the opposite direction for most people — atrophic, pitted scars form from a loss of collagen and tissue, leaving a depression rather than a raised bump, and treatment for that kind of scar (fillers, microneedling, resurfacing) is aimed at rebuilding volume 1. Keloids and hypertrophic scars are the mirror image: an excess of collagen forming a raised bump, so the corrective approach runs the opposite direction — flattening tissue rather than building it up. Recognizing which direction a scar has gone is the first real decision point in treating it.

How should someone actually decide between treatment options?

Because a keloid or a stubborn hypertrophic scar can be treated with several reasonable approaches — injections, silicone, pressure, laser, or surgery paired with an adjunct — the choice often comes down to weighing benefits, risks, and personal priorities rather than there being one obviously correct answer. A structured shared-decision conversation with a clinician, working through what matters most (appearance, comfort, recurrence risk, cost, time commitment) alongside the realistic benefits and downsides of each option, generally produces a better-fitting plan than defaulting to whichever treatment is best known 2. This matters especially for keloids, where recurrence after any single treatment is common enough that the plan needs buy-in for the long haul, not just a first appointment. Someone hoping to get rid of a keloid scar entirely should expect that conversation to cover multiple rounds of treatment rather than a single fix.

Common questions

Generally no — a hypertrophic scar that stays within the original wound's boundaries for its first year or so is unlikely to later transform into a spreading keloid. The two are usually considered distinct patterns from early on, though it can take some months of observation to be fully confident which one a new scar is.

The ear, especially the upper cartilage after a piercing, the chest, the shoulders, and the upper back are among the most keloid-prone sites, likely due to higher skin tension and other local factors in those areas. Hypertrophic scars can occur anywhere an injury or surgical incision happens, without the same site-specific pattern.

Neither is medically dangerous or associated with skin cancer. Both are benign overgrowths of scar tissue; the concerns are cosmetic appearance, itching, tenderness, and, for keloids specifically, continued growth over time without treatment.

Most clinicians look for whether the raised tissue has grown beyond the original wound's edges by around six months to a year. If it has stayed contained but is simply taking a while to flatten, a hypertrophic scar pattern is more likely; growth beyond the original borders at any point is the more specific keloid sign.

No. Keloids show a much stronger family pattern, and having a close relative with keloids meaningfully raises personal risk. Hypertrophic scars are more strongly linked to how a specific wound healed — tension, infection, or delayed closure — than to inherited traits.

Related

Say it back

How would you explain this to someone you love?

Two or three sentences, just as you’d say it. Gale reflects back what you focused on — a mirror, not a quiz.

Talk to a clinician

Gale can help you find a clinician in your state and request a visit.

Find care →

When a growing scar needs a closer look

  • —A scar that keeps expanding rapidly rather than gradually, especially with new pain
  • —Ulceration, bleeding, or an open sore on the surface of a raised scar
  • —A scar with an irregular, asymmetric border or uneven color, which warrants ruling out something other than a keloid or hypertrophic scar

This article explains general patterns that distinguish keloids from hypertrophic scars and is not a diagnosis. A dermatologist can examine a specific scar directly and confirm which pattern it fits before recommending treatment.

References

  1. 1.Boen M, Jacob C (2024). Atrophic Postacne Scar Treatment: Narrative Review. JMIR Dermatology. link ✓That atrophic acne scar treatment (fillers, microneedling, resurfacing, subcision) is aimed at rebuilding lost volume, used as a contrast to explain that keloid/hypertrophic scarring is a collagen-excess problem running in the opposite direction, not a claim about keloid treatment itself.
  2. 2.Agency for Healthcare Research and Quality (2020). The SHARE Approach. Agency for Healthcare Research and Quality (AHRQ). link ✓The five-step SHARE Approach to shared decision making (seek participation, help compare options, assess values, reach a decision together, evaluate), applied generally to choosing among the several reasonable treatment options for a keloid or hypertrophic scar.

2 sources, numbered by first appearance. General health information, not medical advice. AI-assisted editorial content — every citation independently verified. Editorial policy

← Back to the health library