Keloid vs. Hypertrophic Scar: Key Differences

If a scar starts looking puffy, shiny, or oddly firm, it's natural to wonder whether something's gone wrong with the healing process. Raised scars aren't all the same thing, though — they fall into two distinct categories, and telling them apart matters for what to expect next. In this article, we'll cover what separates a hypertrophic scar from a keloid, how each one tends to behave over time, which signs are worth getting checked, and a few common myths that trip people up.

What's the Difference Between a Keloid and a Hypertrophic Scar?

The single biggest tell is boundary. A hypertrophic scar stays confined to the original wound — it's raised, sure, but it doesn't spread past where the injury actually was. A keloid does the opposite: it pushes past the edges of the original cut, burn, or piercing and grows into skin that was never injured in the first place. According to a review that treats a hypertrophic scar's tendency to stay within the original wound margin, and a keloid's tendency to spread beyond it and recur after treatment, as the key features separating the two, that boundary question is the clearest dividing line between them.

Both types can look similar at first glance: red, firm, and slightly raised above the surrounding skin. But because they behave so differently over the following months, lumping them together as "just scar tissue" can lead to the wrong expectations about how — or whether — they'll settle down.

What Is a Hypertrophic Scar?

A hypertrophic scar forms when the body produces more collagen than it needs while closing a wound, and that extra tissue piles up right where the injury happened — not beyond it. You'll typically see these after burns, surgical incisions, or any cut deep enough to reach the dermis.

These scars tend to show up within the first few weeks after a wound closes, thicken over the following months, and then plateau. After that, most start to soften and flatten on their own, and the redness gradually fades. There's an exception worth knowing about: scars over joints or other areas that move and stretch a lot, like the inside of an elbow, can stay tight or even contract, which sometimes makes movement uncomfortable even after the color settles down.

Because hypertrophic scars generally follow a predictable arc toward improvement, the standard approach is often to track how they're progressing before deciding whether any active treatment is needed at all.

What Is a Keloid, and Why Does It Keep Spreading?

A keloid takes that same overproduction of scar tissue and pushes it further, literally. Instead of stopping at the wound's edge, the tissue keeps building outward into skin that was never cut or burned, and it can keep growing for months or, in some cases, years. Unlike a hypertrophic scar, a keloid usually won't resolve on its own.

Researchers have traced this behavior to what's happening deep in the skin, in a layer called the reticular dermis, the lower portion of the dermis where thick collagen bundles live. That's where the inflammatory response driving scar overgrowth tends to originate. According to research linking both keloids and hypertrophic scars to chronic inflammation in the reticular dermis, with the two conditions differing mainly in how intense and how long that inflammation lasts, keloids appear to involve a stronger, more sustained version of the same inflammatory process.

That prolonged inflammatory response also explains why keloids are notoriously prone to recurrence, even after they've been treated. They're more common on the chest, shoulders, and earlobes, and some people are simply more genetically prone to developing them than others.

Keloid vs. Hypertrophic Scar at a Glance

Here's how the two compare across the traits that matter most for figuring out what you're looking at.

Trait	Hypertrophic Scar	Keloid
Growth pattern	Stays within the wound	Spreads beyond the wound
Timeline	Usually plateaus, then softens	Can keep growing for years
Recurrence	Relatively uncommon	Common, even after treatment
Typical approach	Watch and reassess over time	Plan for ongoing management

Keep in mind these are general tendencies, not hard rules. Early on, the two can genuinely look alike, which is part of why an in-person look matters more than a mirror check.

Risks, Red Flags, and When to See a Provider

Most raised scars, hypertrophic or keloid, aren't dangerous. They're a cosmetic and sometimes functional concern rather than a medical emergency. Still, there are a few signs worth flagging to a provider rather than waiting out.

• The scar is spreading past the original wound. That's the hallmark of keloid behavior, and it's worth having assessed early rather than watching it expand.
• It's still growing months after the wound healed. A scar that should have plateaued but keeps enlarging is a reason to check in, not wait it out.
• It's persistently itchy, tender, or getting darker. Ongoing irritation or color changes can be a sign the inflammatory process driving the scar is still active.

If you're not sure which type you're dealing with, that's actually pretty common early on. A provider can usually tell the difference on exam far more reliably than trying to self-diagnose from photos or forums.

Common Myths About Raised Scars

A few misconceptions tend to shape how people think about raised scars, and they're worth clearing up.

• "Any raised scar is a keloid." That's not accurate. Hypertrophic scars, which stay within the wound, are actually more common.
• "It'll eventually go away completely on its own." That's a fair expectation for many hypertrophic scars, but keloids often don't resolve without some kind of intervention, and can keep growing instead.
• "Once it's treated, it's done." Keloids in particular tend to recur, so ongoing follow-up is usually part of the picture rather than a one-and-done fix.

The Bottom Line

Here's the short version: hypertrophic scars stay inside the original wound and tend to improve on their own over months. Keloids grow past the wound's edges, don't reliably resolve without help, and have a real tendency to come back after treatment. Not every raised scar is a keloid. In fact, most aren't.

Like most things involving skin and healing, there's a range of normal here, and individual results and timelines vary from person to person. If you're noticing a scar that's spreading, still growing months later, or just staying uncomfortable, it's worth getting an in-person opinion rather than guessing from a mirror. BeautyStone is a dermatology clinic in Seoul's Hapjeong neighborhood, and if you'd like an evaluation, current consultation options are listed at /en/promotion.

Frequently Asked Questions

Q1. Does a keloid ever shrink or go away on its own?

Not usually. Unlike a hypertrophic scar, which tends to plateau and soften over months, a keloid typically doesn't resolve without some form of intervention and can keep growing for years if left alone.

Q2. How can I tell if my scar is a keloid or just hypertrophic?

The clearest clue is whether the raised tissue stays within the original wound (hypertrophic) or spreads into skin that was never injured (keloid). Early on, though, the two can look alike, so an in-person exam is more reliable than guessing.

Q3. Why do keloids come back after treatment?

Keloids are linked to a stronger, longer-lasting inflammatory response deep in the skin than hypertrophic scars are. That prolonged inflammation is thought to be part of why keloids recur so often, even after they've been treated.

Q4. Am I more likely to develop a keloid?

Some people are more genetically prone to keloids than others, and certain areas, like the chest, shoulders, and earlobes, tend to develop them more often. If you've had a keloid before, it's worth mentioning that history before any new skin procedure.