asbestosis
Meaning of asbestosis: Scarring, not cancer: this is the fibrotic lung disease of asbestos exposure, and it is diagnosed separately from mesothelioma.
Definition of asbestosis
Asbestosis is a long-term lung disease caused by breathing in asbestos fibers, usually over years of work with the material. The fibers settle deep in the lung and set off inflammation that slowly replaces normal elastic tissue with scar tissue. The scarring is permanent, makes the lungs stiff and thickens the barrier that oxygen has to cross.
How does the scarring develop?
Fibers small enough to reach the air sacs are too durable for the immune system to clear. White cells attack them, die, and release enzymes and reactive molecules that damage the surrounding tissue. Repair follows, but repeated injury tips repair into fibrosis, in which collagen replaces the springy tissue that normally lets the lung expand and recoil. The change concentrates in the lower parts of the lung and near the lining. Because scar tissue neither stretches nor passes oxygen well, the lung ends up smaller in volume and less efficient at the one job it has. The process is driven by fibers already in place, so it can continue after exposure has stopped, and the existing fibrosis does not reverse.
What does it do to a person?
Breathlessness on exertion is the usual first complaint, and it advances slowly enough that people often attribute it to age or weight before anything else. A dry cough, tightness in the chest and reduced exercise tolerance follow. Listening to the chest picks up fine crackles at the lung bases, and the fingertips may broaden in a change called clubbing. Breathing tests show a restrictive pattern, meaning reduced volume rather than blocked airflow, along with poorer transfer of oxygen into the blood. Imaging shows scarring at the bases and often plaques on the lining, which record the asbestos exposure even when the lung tissue itself is not badly affected.
How is it different from the asbestos cancers?
| Condition | What it is | Where it sits |
|---|---|---|
| Pleural plaques | Localized scar on the lung lining, not a cancer | Lining of the chest wall and diaphragm |
| Asbestosis | Widespread scarring, not a cancer | Lung tissue itself |
| Mesothelioma | Cancer of the lining | Chest or abdominal lining |
| Lung cancer | Cancer arising in the airway or lung tissue | Lung tissue itself |
The four share one cause and are otherwise separate diagnoses. Having asbestosis does not turn into lung cancer, but the exposure heavy enough to produce asbestosis also raises the risk of the cancers, and tobacco smoke multiplies the lung cancer risk rather than simply adding to it.
Used in a sentence
Pulmonary function testing was ordered to evaluate the extent of asbestosis in the patient with a prior history of shipyard work.
Good to know
Asbestosis refers specifically to the scarring lung disease caused by asbestos fibers and is a separate diagnosis from mesothelioma or lung cancer, even though all three share asbestos exposure as a cause.
Word origin
Where “asbestosis” comes from
Formed from asbestos combined with the suffix -osis, from Greek, indicating a condition or disease process.