Written By: Karen Selby, RN,
Last modified: January 13, 2022

What Is Pleural Thickening?

Pleural thickening is a disease that can be caused by asbestos exposure. Asbestos fibers cause tissue in the lungs to scar, which leads to thickening of the pleural lining. Pleural thickening is incurable but treatable.

Early pleural thickening has no symptoms, however. As more and more rigid pleural scarring forms around the lungs, it becomes harder for them to fully expand.

As the disease progresses, patients commonly experience chest pain and breathlessness, which is also known as dyspnea.

In some cases, pleural thickening is considered an asbestos-related disease.

Pleural Thickening Facts

  • Symptoms may include chest pain and breathing difficulty.
  • It is caused by chronic inflammation of the pleura.
  • Asbestos exposure and associated pleural effusions can cause pleural thickening.
  • Treated with medication and pulmonary rehabilitation.

Is Pleural Thickening Serious?

Pleural thickening can be serious, especially when it reaches more advanced stages.

The presence of pleural thickening is not enough to confirm a pleural mesothelioma diagnosis, but it can be a sign of serious and significant asbestos exposure. Furthermore, pleural thickening may not appear for every mesothelioma patient.

A 2021 research journal reported on the case of a 62-year-old woman with a surgical history of recurrent bilateral pneumothorax and severe difficulty swallowing. She was later diagnosed with malignant pleural mesothelioma but had no pleural thickening or signs of asbestos exposure, making diagnosis difficult.

Because catching mesothelioma in an early stage can lead to a wider range of treatment options, patients with asbestos-related pleural thickening should seek regular cancer screening.

Advanced pleural thickening may close off the space between the two layers of the pleura and encase the lung completely, causing restrictive lung disease. As a result, patients experience decreased lung volume and have to work harder to breathe.

Pleural thickening should not be confused with pleural plaques, another condition caused by asbestos exposure.

What Causes Pleural Thickening?

Any disease that causes acute inflammation of the pleura can lead to pleural thickening, so it is vital to share your history of possible asbestos exposure with your doctor in order to ensure an accurate and timely diagnosis.

The pleural thickening associated with asbestos is often related to prolonged exposure to asbestos. When a person inhales asbestos dust, the microscopic mineral fibers can become embedded in the pleura.

This triggers an inflammatory response that causes a chronic accumulation of fluid in the pleural space. This buildup is called a pleural effusion. The progressive collection of fibrous scar tissue is known as pleural thickening.

A review of studies on the topic found pleural thickening occurs in 5% to 13.5% of asbestos-exposed workers. The condition may arise within a year of exposure, or it may not arise until decades later.

In most cases, there is a latency period of 15 to 20 years between the initial asbestos exposure and a doctor’s diagnosis of pleural thickening.

The causes of pleural thickening include:

  • Chronic pneumonia
  • Tuberculosis
  • Empyema, which is an accumulation of pus in the pleura due to infection
  • Hemothorax, which is an accumulation of blood in the pleura due to chest injury
  • Coronary artery bypass grafting surgery
  • Radiation exposure

These other conditions are more likely to be diagnosed as unilateral pleural thickening, which means they affect only one side of the chest or one lung. Asbestos-related pleural thickening is more commonly diagnosed as bilateral pleural thickening, which means it usually affects both lungs.

What Are Common Pleural Thickening Symptoms?

The most common pleural thickening symptom is breathlessness.

In an early study involving patients with moderate to severe pleural thickening, 95.5% complained of some symptoms of breathlessness, 65% described moderate breathlessness, and 11% described severe breathlessness.

Pleural Thickening Symptoms

  • Breathlessness
  • Difficulty drawing a deep breath
  • Shortness of breath, even with mild exertion
  • Chest pain when drawing a deep breath
  • Pain with coughing
  • Dull, chronic chest pain
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How Is Pleural Thickening Diagnosed?

The most common way to diagnose pleural thickening is with imaging studies such as X-rays MRIs or CT scans.

Doctors can use a few different imaging scans to diagnose pleural thickening:

X-ray Imaging Scans

The condition is usually first spotted through a chest X-ray, in which pleural thickening appears as an irregular shadow of the pleura.

CT Scans

Pleural thickening can be seen on computed tomography scans. CT scans can be used to diagnose pleural plaques and asbestosis. CT scans can detect early signs of pleural thickening when scar tissue is 1-2 mm in thickness.

PET and MRI Scans

Doctors can use positron emission tomography scans and magnetic resonance imaging scans to distinguish between pleural thickening and pleural mesothelioma, a cancer affecting the pleura and often associated with asbestos exposure.

How Is Pleural Thickening Treated?

Although pleural thickening treatment is typically limited to supportive and symptomatic care, some case reports have shown pleurectomy surgery to be effective in progressive cases.

This aggressive treatment, usually reserved for patients with pleural mesothelioma, involves removing parts of the pleura and surrounding the lungs.

In most cases, doctors provide treatments that address each person’s particular symptoms.

For example, prescription medications such as bronchodilators and steroids can make breathing easier for patients.

The best treatments are aimed at easing the symptoms of pleural thickening and improve quality of life.

Pulmonary Rehabilitation

According to a 2015 Australian study, pulmonary rehabilitation can significantly improve quality of life for patients with dust-related respiratory diseases, including pleural thickening.

This type of rehabilitation involves moderate-intensity exercise training to help patients overcome their breathing difficulty and stay physically active.

Smoking Cessation

For patients who smoke, quitting is essential after a diagnosis of pleural thickening. Smoking further reduces lung function and increases the risk of developing other respiratory diseases.

Talk to your doctor about quitting smoking. They can offer supportive care and additional options, such as nicotine replacement and medications, to curb nicotine urges. Following these steps can improve your odds of successfully quitting for good.

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Common Questions About Pleural Thickening

Does pleural thickening mean I have cancer?

Pleural thickening alone is not enough to confirm that you have asbestos cancer. However, it can be a sign of significant asbestos exposure and indicate a high risk for mesothelioma. Advanced pleural thickening can cause restrictive lung disease with severe breathing difficulty.

Can pleural thickening be cured?

Pleural thickening has no cure and is usually limited to supportive treatment. The effects of pleural thickening are irreversible in malignant pleural mesothelioma. Surgery may be an option in some cases to improve breathing difficulty and other respiratory symptoms.

Can pleural thickening be caused by smoking?

Asbestos is the primary cause of pleural thickening. There is data that points to a correlation between smoking and the progression of pleural thickening. Smoking limits lung function and is proven to be a cause of other respiratory diseases such as lung cancer.

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