asbestosis

Asbestosis is the lung scarring caused by breathing in asbestos fibres over many years. If healthy lung tissue is like a soft, springy sponge, asbestosis stiffens it with bands of scar, so the lungs expand less easily and oxygen passes from air to blood less efficiently. It belongs to the family of fibrotic, restrictive lung diseases.

The fibres deposited deep in the lung trigger a slow, self-perpetuating inflammatory reaction. Over decades this lays down collagen scar tissue (fibrosis) in the walls of the alveoli and surrounding interstitium, thickening the delicate air–blood barrier. The disease is dose-dependent — heavier and longer exposure produces worse scarring — and typically appears 15 to 40 years after exposure begins.

Patients develop slowly worsening breathlessness on exertion and a dry cough; examination may reveal fine crackles at the lung bases and, in advanced cases, clubbed fingers. CT shows fibrosis, sometimes with honeycombing, often alongside pleural plaques that betray the asbestos cause. There is no cure and no treatment reverses the scarring; care focuses on oxygen, pulmonary rehabilitation, vaccination, and screening for the lung cancer and mesothelioma to which these patients remain at higher risk.