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Almost everyone has a scar that tells a story, but have you ever wondered why exactly scars form in the first place?

Warning: There are some graphic images of scars in this episode.

Hosted by: Hank Green
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Sources:
http://www.nhs.uk/conditions/scars/Pages/Introduction.aspx
http://www.ncbi.nlm.nih.gov/books/NBK21582/
http://www.news-medical.net/health/What-is-Collagen.aspx
http://www.webmd.com/skin-problems-and-treatments/scars
http://www.huffingtonpost.com/robert-tornambe-md/scar-treatment-_b_830479.html
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3038392/
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2918339/
http://www.aafp.org/afp/2009/0801/p253.html
Pretty much everybody has some scar on their body that tells a story. But why does this weird tissue form in the first place? Well, scarring is, of course, part of out normal healing process. When you get a nasty scrape on your knee, for example, your body produces lots of the structural protein called collagen to help heal that injury. 

Collagen is found in the connective tissue all over your body, it's the stuff that keeps your skin firm, smooth and stretchy. And when your skin is damaged, excess collagen helps fill in the wound with new tissue based on the size, shape, and type of injury. And, this new tissue has a different arrangement of collagen fibers than normal skin tissue, and that is what makes a scar. But scars can also take on different forms, depending on how the healing process takes place.

The most common type of scars are probably hypertrophic scars. In these scars, the buildup of collagen fibers form red, raised patterns on the skin. Over time, they can fade in color and smooth out, so you're left with a less-visible  patch of pale scar tissue. Sometimes wounds have an overgrowth of scar tissue and form keloid scars, which can be itchy, painful, and sometimes regrow even after surgical removal. Pitted, or atrophic, scars look just like they sound. They occur when fat or other tissue underneath the skin is lost in the initial injury, like after severe acne or chicken pox. So when the skin heals over, a sunken pit remains. And contracture scars are frequently caused by burns. The wound shrinks as it heals, which causes twisted skin to form and restrict movement. 

So, there are lots of different scars, but what can we do about them? Some people say that lotions and creams, especially vitamin E oil, will help reduce the appearance of scars. But there's not much scientific evidence to support that. However, there are some treatments out there. For example, corticosteroid injections can help clear up inflammation in hypertrophic and keloid scars allowing the tissue to smooth out. Lase therapy can zap the blood vessels in scar tissue to reduce redness and discoloration, and pitted scars can be smoothed out with injections of dermal fillers. 

When it comes to more severe scarring, the treatments get more intense. Silicone sheets or gels are laid over healing skin to keep it hydrated, allowing it to breathe, and protect it from bacteria, all things that reduce the excessive collagen production that causes scarring. And pressure bandages can be used to help heal widespread, severe scarring, particularly after a skin graft. However both of these treatments can be time-consuming, requiring patients to keep their wounds covered for months. Doctors may also use surgery as a last resort, like to restore movement where scar tissue has made it difficult or painful.

Because everyone can get scars. Doctors and scientists are still working to uncover more effective treatments to reduce scarring and minimize their appearance. In the meantime, we'll have to accept our scars as a part of who we are, great sources of story-telling, and monuments to out bodies' ability to heal themselves.

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