Mesothelioma is a form of cancer that is becoming more and more common. The most common cause of this cancer is exposure to asbestos. When constantly exposed within sufficient protection, asbestos dust and fibres affect the mesothelial cells which make up the mesothelium. The mesothelium is the outer lining that protects some of the body’s most vital organs such as the heart and lungs. The mesothelial cells become abnormal after lengthy periods of constant exposure to asbestos causing an array of problems.