Hypertrophic scars are raised, firm scars that form when your body produces too much collagen during wound healing. Unlike normal scars that gradually flatten and fade, these scars stay thickened and elevated above the surrounding skin. The key feature that defines them: they never grow beyond the borders of the original wound. They’re common, occurring in anywhere from 8% to 67% of burn patients depending on the severity of the injury, and they can develop after surgery, cuts, piercings, or any trauma that breaks the skin.
How They Form
Normal wound healing involves a carefully orchestrated process where your body lays down collagen (a structural protein) to rebuild damaged tissue. Once the wound closes, the cells responsible for this repair work are supposed to wind down and eventually disappear. In hypertrophic scars, that shutdown never happens properly.
The specific cells at the center of the problem are a type of repair cell called myofibroblasts. These cells activate in response to growth signals during healing, contracting the wound edges together and depositing the structural material that closes the gap. Once the skin surface is fully restored, myofibroblasts normally die off. In hypertrophic scarring, they persist, continuing to churn out collagen and other structural proteins long after the wound has closed. The result is a dense, excess buildup of tissue that pushes the scar upward above the skin’s surface.
Several types of immune cells, including platelets, macrophages, and mast cells, contribute to this overactivation. They drive fibroblasts (the precursors to myofibroblasts) into overdrive, creating a feedback loop of excess tissue production. Mechanical tension on the wound makes everything worse. Prolonged pulling force at a healing site ramps up inflammation, promotes new blood vessel growth, and triggers even more collagen production locally.
What They Look and Feel Like
Hypertrophic scars are raised, firm to the touch, and often reddish or darker than the surrounding skin. They may feel tight or itchy, especially during the early months of formation. The texture is noticeably different from normal skin, with a thicker, less pliable surface. Some scars develop a ropy or cord-like quality, particularly over joints where the skin is constantly being stretched.
The defining visual characteristic is that the scar stays within the boundaries of the original wound. If you had a 3-centimeter surgical incision, the raised scar tissue won’t extend past that 3-centimeter line. This is the single most important feature separating hypertrophic scars from their more aggressive counterpart, keloids.
Where They’re Most Likely to Appear
Hypertrophic scars strongly favor areas of the body where skin is under constant tension. The shoulders, neck, chest (especially the breastbone area), knees, and ankles are high-risk zones. Elbows and other joints are also common sites because the skin there stretches and contracts with every movement, putting continuous mechanical stress on healing tissue. The upper arms and back round out the list of frequent locations.
This pattern makes sense given what drives their formation. Areas where the skin is naturally pulled tight experience more tension across any healing wound, which feeds the cycle of inflammation and excess collagen deposition. Wounds on the face, by contrast, tend to heal with less hypertrophic scarring because facial skin is relatively lax and has excellent blood supply.
Hypertrophic Scars vs. Keloids
People often confuse these two conditions because both produce raised, firm scar tissue. The differences matter because treatment approaches and long-term outlook diverge significantly.
- Boundary behavior: Hypertrophic scars stay confined to the original wound. Keloids grow beyond the wound edges, sometimes expanding far past the original injury into healthy surrounding skin.
- Regression: Hypertrophic scars may flatten and improve on their own over months to years. Keloids rarely regress spontaneously and tend to be permanent without treatment.
- Frequency: Hypertrophic scars are significantly more common than keloids in the general population.
- Recurrence: Keloids have a much higher rate of returning after treatment, which is why they’re generally considered harder to manage.
If your raised scar is growing past the edges of your original wound, or if it appeared months after the wound fully healed, you’re more likely dealing with a keloid than a hypertrophic scar.
Silicone Therapy
Silicone gel sheets are one of the most widely used and well-studied treatments for hypertrophic scars. They work through a surprisingly simple mechanism: by trapping moisture against the scar’s surface, they mimic the natural barrier function of healthy skin.
Here’s why that matters. When the outermost layer of skin over a scar becomes dehydrated, it sends chemical signals down to deeper skin cells, essentially telling them to produce more collagen to help retain water. Silicone sheets block this signal by providing a level of moisture retention similar to intact, normal skin. With hydration restored, the overactive collagen production slows down, and the scar gradually softens and flattens.
Current silicone sheet products are designed to be worn up to 24 hours a day, and optimal results typically require 6 to 12 months of consistent wear. That’s a significant commitment, which is why adherence can be a challenge. But for people willing to stick with it, silicone therapy offers a noninvasive option with minimal side effects.
Steroid Injections
For scars that don’t respond to silicone alone, corticosteroid injections directly into the scar tissue are a standard next step. The injections work by suppressing the inflammatory process and slowing collagen production at the site. Most treatment protocols involve a series of injections spaced roughly every 3 to 8 weeks, with results typically visible after two or three sessions. Some practitioners continue until the scar flattens completely, up to a maximum of about six to eight sessions.
The injections can be uncomfortable since the scar tissue is dense and resistant to the needle, but each session is brief. Side effects can include thinning of the skin around the injection site and temporary lightening of skin color, particularly in people with darker skin tones. The concentration and frequency are adjusted based on the scar’s size and location.
Laser Treatment
Pulsed dye lasers target the blood vessels within scar tissue, reducing the redness and vascularity that give hypertrophic scars their characteristic pink or red appearance. These lasers use a 595-nanometer wavelength that’s specifically absorbed by blood vessels, causing them to collapse without damaging surrounding tissue. Studies show measurable improvements in scar color, height, and pliability after a series of treatments.
Some practitioners combine pulsed dye lasers with fractional CO2 lasers for more stubborn scars. The fractional laser creates microscopic columns of damage in the scar tissue, triggering a controlled remodeling process that can improve texture and flexibility. The combination approach has shown better results on both the surface appearance and the overall stiffness of the scar compared to either laser alone.
Reducing Your Risk
Because mechanical tension is one of the strongest drivers of hypertrophic scarring, anything that reduces pulling force on a healing wound lowers your risk. Surgical techniques that minimize wound tension have been shown to cut scar width significantly, from an average of 1.7 centimeters down to 0.7 centimeters in one study comparing tension-reducing approaches.
For everyday wound care, practical steps include keeping the wound well-supported with adhesive strips or tape during the healing period, avoiding activities that stretch the area, and starting silicone therapy early once the wound has closed. Wounds over joints or high-tension areas benefit most from these precautions. If you’ve had hypertrophic scars before, you’re at higher risk of developing them again with future injuries, so early preventive measures carry extra value.