Mesothelioma is an aggressive cancer that forms in the mesothelium — the thin lining that surrounds the lungs, abdomen, heart, and other organs. It is caused almost exclusively by exposure to asbestos, and it typically develops 20 to 50 years after that exposure. This long latency is why people exposed decades ago are being diagnosed today.

This section explains what mesothelioma is in plain language, and links to detailed guides on its symptoms, types, stages, and prognosis.

How Asbestos Causes Mesothelioma

When asbestos fibers are inhaled or swallowed, the microscopic, durable fibers can lodge in the mesothelial lining and remain there for decades. Over time they cause the chronic inflammation, scarring, and cellular damage that can lead to cancer. Because the fibers resist the body’s clearance mechanisms, even relatively limited exposure can, decades later, result in disease. There is no known safe level of asbestos exposure.

The Main Types of Mesothelioma (by location)

  • Pleural mesothelioma — in the lining of the lungs; the most common form (~75-80% of cases).
  • Peritoneal mesothelioma — in the lining of the abdomen; the second-most common.
  • Pericardial (heart lining) and testicular mesothelioma are rare.

Detailed Guides

Understanding where and how the exposure happened is central to both treatment context and legal claims. See the types of asbestos, how to identify asbestos, and the product and manufacturer database.

This information is educational and is drawn from established medical sources such as the American Cancer Society and the National Cancer Institute. It is not medical advice and is not a substitute for diagnosis and treatment by a qualified physician. Always consult your own doctor about your health.