Mesothelioma Mesothelioma is a rare and aggressive form of cancer that primarily affects the lining of the lungs, heart, or abdomen. It is most commonly associated with asbestos exposure. In this article, we'll break down everything you need to know about mesothelioma in a simple and clear way. What is Mesothelioma? Mesothelioma is a type of cancer that develops in the mesothelium, a thin layer of tissue that covers most of your internal organs. The most common type is pleural mesothelioma, which affects the tissue surrounding the lungs. Other types include peritoneal mesothelioma (abdomen), pericardial mesothelioma (heart), and testicular mesothelioma (testes). Causes of Mesothelioma The primary cause of mesothelioma is exposure to asbestos, a group of minerals made of microscopic fibers that were once widely used in construction, manufacturing, and other industries. When asbestos fibers are inhaled or ingested, they can become lodged in the mesothelium, causing inflammation and s...