When skin is injured, fibrous tissue called scar tissue forms over the wound to repair and protect the injury. In some cases, extra scar tissue grows, forming smooth, hard growths called keloids.

Keloids can be much larger than the original wound. They’re most commonly found on the chest, shoulders, earlobes, and cheeks. However, keloids can affect any part of the body.

Although keloids aren’t harmful to your health, they may create cosmetic concerns.

Keloids come from the overgrowth of scar tissue. Keloid scars tend to be larger than the original wound itself. They may take weeks or months to develop fully.

The symptoms of a keloid can include:

  • a localized area that is flesh-colored, pink, or red
  • a lumpy or ridged area of skin that’s usually raised
  • an area that continues to grow larger with scar tissue over time
  • an itchy patch of skin

While keloid scars may be itchy, they’re usually not harmful to your health. You may experience discomfort, tenderness, or possible irritation from your clothing or other forms of friction.

Keloid scarring can form on large areas of your body, but this is generally rare. When it happens, the hardened, tight scar tissue may restrict movement.

Keloids are often more of a cosmetic concern than a health one. You may feel self-conscious if the keloid is very large or in a highly visible location, such as on an earlobe or the face.

Most types of skin injury can contribute to keloid scarring. These include:

An estimated 10 percent of people experience keloid scarring. Men and women are equally likely to have keloid scars. People with darker skin tones are more prone to keloids.

Other risk factors associated with keloid formation include:

  • being of Asian descent
  • being of Latino descent
  • being pregnant
  • being younger than 30 years of age

Keloids tend to have a genetic component, which means you’re more likely to have keloids if one or both of your parents have them.

According to one study, a gene known as the AHNAK gene may play a role in determining who develops keloids and who doesn’t. Researchers found that people who have the AHNAK gene may be more likely to develop keloid scars than those who don’t.

If you have known risk factors for developing keloids, you may want to avoid getting body piercings, unnecessary surgeries, and tattoos. Learn options for getting rid of keloids and other scars that are common on the legs.

Keloids are sometimes confused with another more common type of scar called hypertrophic scars. These are flat scars that can range from pink to brown in color. Unlike keloids, hypertrophic scars are smaller, and they can go away on their own over time.

Hypertrophic scars occur equally among genders and ethnicities, and they’re commonly caused by various forms of physical or chemical injuries, such as piercings or harsh fragrances.

At first, fresh hypertrophic scars can be itchy and painful, but the symptoms subside as the skin heals. Learn about all your hypertrophic scar treatment options.

The decision to treat a keloid can be a tricky one. Keloid scarring is the result of the body’s attempt to repair itself. After removing the keloid, the scar tissue may grow back again, and sometimes it grows back larger than before.

Before any medical procedures, try considering at-home treatments. Moisturizing oils, which are available online, can help to keep the tissue soft. These might help reduce the size of the scar without making it worse. Keloids tend to shrink and become flatter over time, even without treatment.

Initially, your doctor will probably recommend less-invasive treatments, such as silicone pads, pressure dressings, or injections, especially if the keloid scar is a fairly new one. These treatments require frequent and careful application to be effective, taking at least three months to work. Learn about other home remedies for old scars.

In the case of very large keloids or an older keloid scar, surgical removal may be recommended. The rate of return for keloid scarring after surgery can be high. However, the benefits of removing a large keloid may outweigh the risk of postsurgery scars.

Cryosurgery is perhaps the most effective type of surgery for keloids. Also called cryotherapy, the process works by essentially “freezing” away the keloid with liquid nitrogen.

Your doctor may also recommend corticosteroid injections after surgery to reduce inflammation and lower the risk of the keloid returning.

For certain types of scars (including some keloids), your doctor may recommend laser treatment. This treatment resurfaces the keloid and surrounding skin with high beams of light in an effort to create a smoother, more toned appearance.

However, there’s a risk that laser treatment can make your keloids worse by causing increased scarring and redness. While these side effects are sometimes better than the original scar, you may still expect there to be some form of scarring. Laser treatment is used for other types of skin scarring, all with similar benefits and risks.

Treatments for keloid scarring can be difficult and not always effective. For this reason, it’s important to try to prevent skin injuries that could lead to keloid scarring. Using pressure pads or silicone gel pads after an injury may also help prevent keloids.

Sun exposure or tanning may discolor the scar tissue, making it slightly darker than your surrounding skin. This can make the keloid stand out more. Keep the scar covered when you’re in the sun to prevent discoloration. Find out more about sunscreen and other ways you can protect your skin.

Although keloids rarely cause adverse side effects, you may dislike their appearance. You can have a keloid treated at any time, even years after it appears. So if a scar is bothering you, have it checked out.