The mesothelium is a protective membrane that covers organs throughout the body, including the lungs and chest cavity. Cancer that forms in these linings is called mesothelioma. This type of cancer can occur near the lungs or abdomen, and can cause a wide variety of vague symptoms. Mesothelioma is primarily caused by long-term asbestos exposure, so anyone who has worked around asbestos is at a significant risk of developing this cancer. Mesothelioma: Who Gets It Mesothelioma, although a serious form of cancer, is quite rare. Only about 2,000 new cases of mesothelioma are diagnosed each year. Up to 80 percent of all cases are linked to asbestos exposure — although some people who are diagnosed with mesothelioma have never been around obvious sources of asbestos. Asbestos is found in: Insulation Brake materials in cars Cement Textiles Mesothelioma strikes men far more often than women, and it also tends to occur later in life. Mesothelioma isn't usually diagnosed until about age 60. Mesothelioma: Where It Is Found Typically, symptoms of mesothelioma don't show up until decades after the initial asbestos exposure. Mesothelioma can be difficult to diagnose, since early symptoms, like a cough or stomach pain, can easily be mistaken for a simple respiratory infection or just a persistent stomachache. It may also mimic the flu, bronchitis, or pneumonia. Which specific symptoms occur depends on where the cancer is located. Most often, mesothelioma is found in the chest (pleural mesothelioma); only about 20 percent of mesothelioma cases initially develop in the abdominal cavity (peritoneal mesothelioma). Mesothelioma in the tissues around the heart and reproductive organs can also occur, but is extremely unusual. Pleural Mesothelioma: Symptoms Some common symptoms of mesothelioma in the chest include: Persistent cough Unexpected weight loss Shortness of breath Difficulty swallowing Hoarse voice Fever Nausea Weakness and fatigue Abdominal discomfort Chest pain Back pain Swelling of the face and arms Peritoneal Mesothelioma: Symptoms Symptoms of mesothelioma in the abdomen include: Abdominal pain Abdominal bloating Weight loss Nausea and vomiting Anyone who experiences these symptoms and has been exposed to asbestos should be examined by a doctor. The earlier mesothelioma is diagnosed and treated, the better the odds of slowing down its progression. Mesothelioma: Getting a Diagnosis Mesothelioma can be diagnosed with the help of a chest X-ray, a computed tomography (CT) scan, a positron emission tomography (PET) scan, or magnetic resonance imaging (MRI) to spot tumors in the chest or abdominal areas. Tissue samples, taken from abnormal areas seen on an imaging test, are examined in the laboratory and are used to confirm a diagnosis of mesothelioma. Mesothelioma is difficult to treat. Once it's diagnosed, the cancer is typically in an advanced stage. The average survival time is only one or two years after diagnosis. The five-year survival rate for mesothelioma is about 10 percent. If you've ever worked around asbestos or materials that may contain it, it's important to recognize the potential warning signs of mesothelioma. Early recognition and treatment provide the best possible chance of managing mesothelioma and minimizing associated complications.