fibroses

Fibrosis is the excessive accumulation of fibrous connective tissue, typically as a response to chronic injury or inflammation. The plural term fibroses is used to describe fibrotic processes in multiple tissues or organ systems. In fibroses, chronic damage triggers activation of fibroblasts into myofibroblasts and overproduction of extracellular matrix, especially collagen, leading to tissue stiffening and impaired function.

Causes include chronic infections, autoimmune diseases, metabolic disorders, toxins, ischemia, and persistent mechanical stress. The course and prognosis depend on the organ involved and the underlying cause.

Common organ-specific fibroses include hepatic fibrosis, pulmonary fibrosis, renal fibrosis, and cardiac fibrosis, as well as systemic sclerosis. Hepatic fibrosis results from hepatitis, alcohol use, or nonalcoholic fatty liver disease and can progress to cirrhosis. Pulmonary fibrosis involves scarring of lung tissue and may be idiopathic or associated with connective tissue diseases or environmental exposures, causing progressive dyspnea and cough. Renal fibrosis reflects chronic kidney injury and contributes to chronic kidney disease. Cardiac fibrosis occurs after myocardial injury or with chronic pressure overload, contributing to diastolic dysfunction and heart failure. Systemic sclerosis is a systemic fibrotic condition affecting skin and internal organs.

Diagnosis uses imaging such as ultrasound elastography, CT, or MRI, and sometimes tissue biopsy; biomarkers may support assessment but are not definitive. Treatment aims to slow progression by addressing the underlying cause and, in some diseases, by antifibrotic medications such as pirfenidone or nintedanib for pulmonary fibrosis. Supportive care and organ-specific management are important, and liver failure due to advanced liver fibrosis may require transplantation. Prognosis varies with disease, severity, and response to therapy. Fibroses are common sequelae of chronic injury and remain an active area of clinical research.