Fibrosis refers to the formation and development of excess fibrous connective tissue in an organ or tissue, often as a response to injury. It can occur in various organs such as the liver, lungs, kidneys, and skin. The process involves the proliferation of fibroblasts, which are cells responsible for producing collagen and other proteins that form the extracellular matrix. Fibrosis can be a natural healing response to tissue injury or it may result from chronic inflammation or infection. However, excessive fibrosis can lead to organ dysfunction and impair normal functioning of organs.