Any symptoms that suggest a physical illness but seem to have no medical cause can be categorized as a somatoform disorder. An example could be someone that has extreme pain in their back with tests showing nothing wrong with it, or an individual who is unable to move their right arm for no apparent reason, neither medical or caused by substance use or other mental disorder.
Unfortunately, because the disorder presents as a physical illness, individuals suffering from somatoform disorders may become fixated on their health problems and experience great anxiety and distress over the fact that doctors can't seem to find what's wrong. This may even promote heightened sensations that could exacerbate the problem.
The somatoform disorders consist of conversion disorder, somatization and pain disorders, hypochondria, and body dysmorphic disorder. Conversion disorder involves symptoms of a neurological disorder, such as paralysis or blindness, with no medical explanation (often thought to be caused by excessive anxiety), while somatization disorder often includes feelings of pain or other bodily symptoms and occurs in an individual with an extensive medical history prior to the age of 30. Pain is the symptom most prevalent in pain disorders, and is thought to occur after a traumatic experience, and hypochondria involves individuals who believe they have a disease when tests show they do not, such as someone who thinks they have a brain tumor because of a headache. Lastly, body dysmorphic disorders are characterized by obsessing over a physical aspect of their own body (real or imagined), often exaggerating it. For example, someone might think a small mole on their skin is so hideous that they work to cover it up constantly throughout the day or always wear clothes that hide it.
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On the other hand, dissociative disorders include a disruption or breakdown in mental functioning, including aspects of memory and identity. The dissociative disorders include dissociative identity disorder, dissociative fugue, dissociative amnesia, and depersonalization disorder. Many of these disorders may arise due to the impact of a traumatic experience.
Dissociative identity disorder, which used to be referred to as multiple personality disorder, involves the existence of two or more personalities within an individual. They may seem to switch between these separate personalities, especially when under stress, which will often have their own name and attributes including voice and behavioral characteristics. Dissociative amnesia is often co-occurent with dissociative identity disorder, and includes lack of memory for a specific event, person, or even for a long-span of their life. On the other hand, dissociative fugue occurs when someone suddenly seems to forget their identity and life, and will often develop a new identity for themselves and when they recover have no recollection of their fugue state. Lastly, depersonalization disorder involves a person who feels detached from their life, emotions, thoughts, and identity.
Somatoform disorders can often be treated through cognitive-behavior therapy and methods of lifestyle changes to reduce stress, while dissociative disorders improve most through talk therapy, hypnosis, and guided imagery.