Somatoform disorder (also known as Briquet's syndrome) is a mental disorder characterized by physical symptoms that mimic physical disease or injury for which there is no identifiable physical cause. The symptoms that result from a somatoform disorder are due to mental factors. In people who have somatoform disorder, medical test results are either normal or don't explain the person's symptoms. People who have this disorder may undergo several medical evaluations and tests to be sure that they do not have an illness related to a physical cause or central lesion. Patients with this disorder often become very worried about their health because the doctors are unable to find a cause for their health problems. Their symptoms are similar to the symptoms of other illnesses and may last for several years.