Asbestosis is a lung disease that occurs from breathing in asbestos fibers. When asbestos is inhaled, it causes scar tissue (fibrosis) to form in the lungs, which are then unable to expand and contract normally. Severity depends on the duration of exposure and the amount breathed in to the lungs. Symptoms may not be apparent for many years after the asbestos exposure.
Asbestos fibers were commonly used in construction before 1975. Asbestos exposure occurred in industries such as: asbestos mining and milling, construction and fireproofing. Cigarette smoking increases the risk of getting asbestos-related diseases.