Mesothelioma is a type of cancer that can affect either the lining of the lungs, the lining of the stomach, or the lining of the heart. Much less frequently, mesothelioma can also affect the tissues surrounding the testicles. Asbestos exposure is the leading cause of mesothelioma, and sometimes, symptoms don't appear for a decade or more after this exposure. Although this type of cancer is rare, about 3,000 people are diagnosed with it each year in the United States.

What Is Mesothelioma?

The lining inside the chest and abdomen, called the mesothelium, is affected by mesothelioma. The healthy cells in the mesothelium manufacture a liquid that helps organs move easily during breathing and other body movements. In mesothelioma cases, these cells begin to reproduce rampantly. This often causes cancerous tissues to surround organs, which prevents them from moving and working as they should.

What Causes Mesothelioma?

The most common cause of mesothelioma is exposure to asbestos. Asbestos is a group of naturally occurring minerals that consist of bundles of fibers that can separate out into thin threads. Asbestos fibers resist chemicals, heat, and fire, and they also don't conduct electricity. These attributes made asbestos a common material used in many industries for decades. When asbestos particles become airborne, they can be inhaled or swallowed. When inhaled, asbestos fibers can lead to pleural mesothelioma, or cancer in the outer lining of the lungs, or pericardial mesothelioma, which is cancer in the heart sac. When ingested, asbestos fibers can affect the lining of the abdominal cavity, causing peritoneal mesothelioma.

How Asbestos Exposure Can Cause Mesothelioma

It usually takes many years for asbestos fibers to trigger mesothelioma in the body. In some people, the cancer might not appear for 60 years or longer. And some people can have exposure to asbestos without ever developing mesothelioma. For those who do develop it, the fibers settle in the chest or the abdomen, where they slowly cause irritation over time. Doctors aren't sure exactly how the irritation causes the cells to mutate and grow out of control.

Who Is at Risk of Mesothelioma?

The longer the asbestos exposure is, the greater a person's risk of developing mesothelioma is. Some of the most at-risk occupations include construction workers, factory workers, shipbuilders, textile mill workers, insulators, firefighters, and automotive repair workers. People who regularly work with asbestos might also bring the fibers home on their clothing, exposing family members. Those with a family history of mesothelioma are also at a higher risk for developing the disease. Receiving radiation treatment to the chest for another type of cancer can also increase the risk of mesothelioma.

Symptoms and Treatment Options

Symptoms of pleural mesothelioma include painful coughing, shortness of breath, chest pain, unexplained weight loss, and unusual lumps under the skin on the chest. Symptoms of peritoneal mesothelioma include unexplained weight loss, nausea, and abdominal pain and swelling. With pericardial mesothelioma, common symptoms include chest pain and difficulty breathing. Treatment options depend on the type of mesothelioma and the extent of the tumors. Patients may be candidates for surgery, chemotherapy, radiation therapy, immunotherapy, and/or targeted therapy, which involves special drugs that target blood vessel formation.


When a family member has mesothelioma, care will be necessary to ensure their comfort. Many who are diagnosed with mesothelioma have a poor prognosis, meaning their health may decline rapidly. A caregiver will need to monitor their daily health, administering medications and noticing any changes in health to report to physicians. Offering companionship will be another important part of caregiving, comforting and listening as needed. Decisions will also need to be made about treatments, finances, legal situations, insurance, and end-of-life details. When a patient is no longer able to manage daily care activities such as bathing, dressing, and eating, a caregiver will need to step in to provide for these needs.