Mesothelioma is caused by certain changes to the way the cells that line the organs function, especially how they grow and divide into new cells. Often, the exact cause of the cell change is unknown. Learn more about how cancer develops at What Is Cancer?
A risk factor is anything that increases the chance of getting a disease. Being exposed to asbestos can increase the risk mesothelioma. Most people with mesothelioma have worked or lived in places where they inhaled or swallowed asbestos, which has been used in the building and textile industries. After being exposed to asbestos, it usually takes a long time for mesothelioma to form. Living with a person who works near asbestos is also a risk factor for mesothelioma. Not every person with one or more of these risk factors will develop mesothelioma. And it can develop in some people who don't have any known risk factors.
Talk to your doctor if you think you may be at risk.