Asbestosis is a respiratory disease caused by inhaling asbestos fibers.

Inhaling asbestos fibers can cause scar tissue (fibrosis) to form inside the lung. Scarred lung tissue does not expand and contract normally, and cannot perform gas exchange. The severity of the disease depends upon the duration of exposure to asbestos and the amount inhaled.

Asbestos fibers were commonly used in construction before 1975. Asbestos exposure occurs in asbestos mining and milling industries, construction, fireproofing, and other industries. In families of asbestos workers, exposure can also occur from particles brought home on the worker's clothing.

Asbestos-related disease includes pleural plaques (calcification), malignant mesothelioma, and pleural effusion. Mesotheliomas may develop 20 - 40 years after exposure. Workers today are less likely to develop asbestos-related disease because of government regulations.

Cigarette smoking increases the risk of developing the disease. The incidence is 4 out of 10,000 people.

• Shortness of breath on exertion
• Cough
• Tightness in the chest
• Chest pain

Possible additional symptoms include the following:

• Nail abnormalities
• Clubbing of fingers

When listening to the chest with a stethoscope (auscultation), the doctor may detect a crackling sound.

• Chest x-ray
• Pulmonary function tests
• CT scan of the lungs
• Gallium lung scan

There is no cure available. Stopping further exposure to asbestos is essential. To ease symptoms, postural drainage, chest percussion, and vibration can help remove secretions from the lungs.

The doctor may prescribe aerosol medications to thin secretions. People with this condition may need to receive oxygen by mask or by a plastic piece that fits into the nostrils. Certain patients may require lung transplantation.

You can ease the stress of this illness by joining a support group whose members share common experiences and problems. See lung disease - support group.

The outcome depends upon the duration and extent of the exposure. Patients who develop malignant mesothelioma have a poor probable outcome, with 75% of those affected dying within 1 year.

• Malignant mesothelioma
• Pleural effusion

Call for an appointment with your health care provider if you suspect that you've been exposed to asbestos or if you have unexplained symptoms.

In people who are exposed to asbestos, early screening by chest x-ray may help prevent asbestosis.

Pupavath S, Godwin JD. Imaging of interstitial lung disease. Radiol Clin North Am. May 2005;43:589-599.

Glazer CS, Newman LS. Occupational interstitial lung disease. Chest. September 2004;25:467-478.

English JC, Leslie KO. Pathology of the pleura. Clin Chest Med. June 2006;27:157-180.