Unlike pleural plaques, diffuse pleural thickening is often accompanied by distressing symptoms, the most common being shortness of breath, which is experienced by over 95% of the patients. In the majority of cases, diffuse pleural thickening is the result of past asbestos exposure and the condition appears within 3 to 34 years after the first contact with airborne fibers. Although this lung condition is not malignant, it often develops into mesothelioma, particularly if the individual has a long history of asbestos exposure.

Initially, diffuse pleural thickening does not cause any distress to the patient, but as the illness progresses, they will start experiencing one or more of the following symptoms:

• chest tightness
• shortness of breath
• chest pain which intensifies with physical exertion
• difficulty breathing
• a persistent cough
• reduced movement of the chest wall