What Are Pleural Plaques?
Pleural plaques are chalky buildups of collagen, a protein naturally found in the body. Pleural plaques usually develop as part of the body’s natural immune response being exposed to asbestos.

When asbestos fibers are inhaled or swallowed, the body’s immune system attempts to eliminate them. However, asbestos fibers are so strong that the body is unable to break them down. Asbestos pleural plaques are the body’s attempt to encircle and isolate them.
While asbestos fibers can settle in different parts of the body, pleural plaques can form when they settle in the pleura (the lining of the lungs).
There are two parts to the pleura:
- Parietal pleura: This part of the pleura lines the diaphragm and chest wall. Most pleural plaques develop here.
- Visceral pleura: The visceral pleura lines the inside of the lungs. Though rare, pleural plaques can also develop in this part of the pleura.
These fibers slowly irritate healthy lung tissue depending on where they settle in the pleura. Over time, the body’s immune response to these fibers causes pleural thickening, the hardening of collagen, and the formation of scar tissue. In an X-ray, calcified pleural plaques will present as translucent white deposits on the lungs.
Pleural plaques rarely cause symptoms, but in some cases, chest pain when breathing or a persistent cough may be reported. These symptoms are generally mild.
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Are Pleural Plaques Harmful?
No — unlike some other asbestos-related diseases, pleural plaques are generally not harmful.
Most doctors suggest that patients with pleural plaques do not need any form of medical intervention.
However, because pleural plaques often develop due to past exposure to asbestos, they may mean victims have an increased risk of related conditions, including asbestos-related lung diseases or malignant (cancerous) mesothelioma.
- Pleural plaques are known as a marker of asbestos exposure.
- They are the most common asbestos-related disease.
- Pleural plaques occur in 50% of people who suffered from long-term asbestos exposure.
- Pleural plaques are typically not found in the general population, though the true incidence rate is unknown due to a lack of screening.
Causes of Pleural Plaques
Researchers believe that asbestos exposure is the main cause of pleural plaques.
In most cases, pleural plaques will develop only after prolonged asbestos exposure. Because of this, those who regularly worked in asbestos-heavy jobs are at a higher risk of pleural plaques.
Workers with a higher risk of asbestos exposure include:
- Boilermakers
- Construction workers
- Factory workers
- Firefighters
- Industrial workers
- Miners
- Military veterans
- Shipbuilders
- Steel mill workers
- Textile mill workers
These workers had a high risk of asbestos exposure prior to the early 1980s, as this was when widespread restrictions on asbestos began. However, asbestos-related diseases can take 10-50 years to develop after exposure.
It is also possible to have secondary asbestos exposure, which could happen when a spouse or household member breathed in asbestos fibers when they washed the clothes of a construction worker, for example.
Studies have found that a high rate of patients with malignant pleural mesothelioma and other asbestos-related diseases also have pleural plaques.
A 2019 report from researchers at the Icahn School of Medicine at Mount Sinai also suggested that talc may possibly contribute to the development of asbestos-related pleural plaques. Asbestos fibers have been found in some samples of talc products like baby powder.
How Pleural Plaques Form
The development of pleural plaques seems to be almost entirely due to the body’s inability to dislodge or expel asbestos fibers.
When asbestos fibers are inhaled into the pleura, they get stuck in the body and irritate the surrounding tissues. The pleura can become inflamed, and the tissue damage causes the immune system to react.
The body attempts to use proteins such as collagen to cover the damaged tissue. Since the lodged asbestos fibers cannot be removed by the body, the collagen builds up in the damaged tissue area.
The tissue then hardens and forms pleural plaques. However, pleural plaques do not develop immediately.
Like all asbestos-related diseases, pleural plaques have long latency periods, meaning it can take decades for them to present after someone was first exposed to asbestos.
Symptoms of Pleural Plaques
Typically, pleural plaques do not cause any symptoms at all. If symptoms are experienced, they are generally mild.
Symptoms of pleural plaques may include excessive coughing and pain while breathing and coughing.
Some researchers believe that significant pleural plaque buildup may also be associated with slightly diminished lung function.
It is rare that an individual with pleural plaques experiences severe shortness of breath. If shortness of breath is continually present, a medical professional should be consulted to determine if another illness or disease is the cause.

We’re here to answer any questions you have about pleural plaques or mesothelioma.
Diagnosis of Pleural Plaques
Since pleural plaques are usually asymptomatic, a diagnosis typically only comes after an individual visits a physician for other reasons.
Pleural plaques can be found using diagnostic techniques like:
- Biopsies
- Computed tomography (CT) scans
- X-rays
Patients can live with pleural plaques for decades without even knowing that they have them, and they likely wouldn’t know unless they had an X-ray or a chest CT scan for another unrelated condition.
X-Rays and Pleural Plaque Diagnosis
Through a chest X-ray, radiologists use electromagnetic waves to see inside the chest and chest wall.
If pleural plaques or strange masses show up in the pleural space, patients should ask their medical providers about the risk of lung cancer or mesothelioma.
A medical provider can best assess a patient’s risk and determine if they require further testing for other asbestos-related diseases.
CT Scans and Pleural Plaque Diagnosis
Through a CT scan, radiologists take a series of high-resolution X-ray images to get a more in-depth look inside the body.
Doctors can typically find masses on the lungs or pleura, but these diagnostic tests cannot always determine whether the mass represents cancer or a benign pleural plaque. This is where biopsies come into play.
Biopsies and Pleural Plaque Diagnosis
Through a biopsy, doctors take a small sample of the mass to determine if the tissue is cancerous or a pleural plaque. A biopsy is the only way to determine a cancer diagnosis, including mesothelioma.
Once a biopsy has been confirmed, health care professionals can recommend treatment plans.
Treatment & Prognosis for Pleural Plaques
In the overwhelming majority of pleural plaque cases, treatment is not necessary.
People can live with pleural plaques for decades with no symptoms, and they can live full and healthy lives without any reduced lung function or capacity.
Most doctors believe that the pleural plaques themselves are unlikely to progress and impede breathing.
Likewise, the prognosis — or expected health outlook — for patients with pleural plaques is usually positive.
Although pleural plaques alone do not require any type of treatment, it is important to remember that a diagnosis could indicate a higher risk factor for other asbestos-related diseases like mesothelioma.
Pleural Plaques and Mesothelioma
There is no direct link between the presence of pleural plaques and mesothelioma. However, both conditions are related to asbestos exposure.
Any individual who has had prolonged exposure to asbestos is at greater risk of both pleural plaques and mesothelioma. That is because of the asbestos fibers that get lodged in the lungs and cause damage to the pleura tissue.
Even if it happened decades ago, asbestos exposure could lead to the development of pleural plaques or mesothelioma today.
Patients who worked in a high-risk occupation for asbestos exposure such as mining or construction work — or who have developed pleural plaques — should speak with their doctor about the risk of mesothelioma and what they can do to protect themselves.
While there is no way to undo the health risks associated with occupational asbestos exposure, doctors can recommend what actions you should take if symptoms of serious diseases develop.
Download our Free Symptoms Checklist to track any signs of mesothelioma and share it with your doctor so you can get an accurate diagnosis.
Next Steps for Patients With Pleural Plaques
While pleural plaques themselves are not dangerous, they could be an early risk factor for more dangerous asbestos diseases.
You should speak with a doctor immediately if you worked in a job that exposed you to asbestos. Doctors can help you determine if you have pleural plaques — or other pleural diseases — and what treatment options are available to you.
Mesothelioma Hope also has a support team that can answer any questions you may have about pleural plaques and mesothelioma.
We can help you:
- Assess your options for medical treatment
- Find top mesothelioma doctors in your area
- See if you can receive financial compensation after a diagnosis
Learn all the ways we can support patients and their families — contact our team today.
Pleural Plaques FAQs
What are pleural plaques?
Pleural plaques are chalky buildups of collagen in the lining of the lungs. They are benign (non-cancerous) and typically asymptomatic.
Pleural plaques form as the body tries to protect itself from asbestos fibers that have become lodged in the pleura.
Are pleural plaques serious?
No. Pleural plaques themselves are not serious, as they do cause health problems.
However, pleural plaques are often a sign that you have been exposed to asbestos. Those who have accidentally inhaled or ingested asbestos fibers are at risk of a number of serious health problems, including asbestosis and mesothelioma.
Can pleural plaques turn into mesothelioma?
No. Pleural plaques do not turn into mesothelioma or any sort of cancerous tumor.
However, those with pleural plaques are at a higher risk of developing mesothelioma, as pleural plaques are a sign of asbestos exposure.
If you have been exposed to asbestos, even if the exposure took place decades ago, talk with your doctor to determine if you are at risk for other illnesses and how to properly monitor your health.
Can pleural plaques cause COPD?
Pleural plaques themselves do not cause chronic obstructive pulmonary disease (COPD).
Unfortunately, exposure to asbestos is a known risk factor for COPD and other respiratory conditions. Inhaling asbestos fibers can irritate and scar the lung tissue, leading to the development of COPD and other lung diseases.
Can pleural plaques kill you?
No. Pleural plaques do not require treatment, as they are typically asymptomatic and do not have an effect on your health.
It is important to note that pleural plaques are known as a marker of asbestos exposure, and inhaling or ingesting asbestos fibers can lead to the development of deadly diseases like mesothelioma.