Mesothelioma is a rare form of cancer most often found in people who work with, or have been exposed to the dust byproduct of the mineral asbestos. Scientists remain uncertain as to why some people develop mesothelioma, and others who are exposed to asbestos products for large parts of their working lives do not develop the disease. A difficult medical condition to diagnose, mesothelioma symptoms vary depending on the area of the body affected by the disease. When the disease is located in the abdomen or lungs, it is much easier to detect than some of the more rare forms of the disease.

When asbestos particles settle in the lungs of a human being they can cause the cells in the tissue surrounding the lungs, known as the mesothelium, to mutate and grow uncontrollably into cancerous cells. When the lungs are affected by mesothelioma, the disease is known as pleural malignant mesothelioma and has a set of symptoms unique to the medical condition. Pleural mesothelioma symptoms are largely located in the chest and lungs, including chest pain around the rib cage and difficulty breathing. Other symptoms include a persistent cough and a large weight loss that is unexplainable.

Because asbestos is usually inhaled through the nose and mouth, the most common destination for particles of asbestos dust to settle is the stomach. When these particles settle in the stomach the symptoms present themselves in the abdomen as a series of painful problems around the abdomen. Known as peritoneal mesothelioma, the symptoms of this painful medical condition include a swollen abdomen, often with lumps under the skin as cancerous cells grow into tumors in the tissue around the abdomen. As with pleural mesothelioma, the peritoneal form of the disease also causes unexplained weight loss in those affected.

Other forms of mesothelioma are also known, but are difficult to diagnose and treatments often offer little chance for a cure. The growth of cancerous cells in mesothelioma is one of the most difficult medical conditions for scientists to study and find out why human beings become infected. Some of the rare forms of mesothelioma have difficult symptoms to identify, such as those when the tissues around the heart are affected by the disease. This form of the disease is known as pericardial and is characterized by symptoms which could be mistaken for those of heart problems, such as chest pains and breathing problems. Mesothelioma can also affect the tissue surrounding the testicles in male bodies. During this form of the disease the first symptoms to manifest themselves are the swelling of the testicles and the formation of a mass beneath the skin.

Because many of the symptoms of mesothelioma can also be spotted as warning signs of other illnesses, this makes the disease very difficult to spot and diagnose. In many cases the symptoms of mesothelioma are initially diagnosed as other medical conditions. As the condition progresses the symptoms of mesothelioma often become more apparent and painful, making them more obvious to a physician.