Hypertrophic Scars and Keloid Scarring - Hypertrophic Scars are thick raised scars that are due to overproduction of collagen within a wound. This type of scarring is related to an over response to the original trauma or injury. These scars do not grow beyond the boundaries of the original injury. Keloid Scars are similar but are not the same thing as a hypertrophic scar. Keloid scars are also an abnormal response to injury but they can grow outside the boundaries of the original injury, and may continue to grow over time.