Fibrosis

Fibrosis is the excessive accumulation of fibrous connective tissue, chiefly collagen produced by fibroblasts, in an organ or tissue as part of the body's response to injury. A limited amount of this scarring is a normal part of wound healing, but when the process becomes excessive or chronic, most often from repeated injury or ongoing inflammation, the resulting scar tissue thickens and stiffens the affected organ and can permanently impair its function. It can occur throughout the body, including the lungs, liver, kidneys, heart, and brain, and severe fibrosis of the liver, for example, can progress to cirrhosis; because of this wide reach it is best understood as a shared pathological process across many diseases rather than a single named condition.