Somatoform disorders are mental illnesses that cause physical symptoms like pain that cannot be connected to any physical cause. Suffers are not “faking” symptoms; the pain and other complications they experience are real. Symptoms vary depending on the type of somatoform disorder, which includes Briquet’s syndrome, with symptoms involving several different organs and body systems, and undifferentiated somatoform disorder, which includes hypochondriasis, a preoccupation with concern that the suffer has a very serious illness.