International Statistical Classification of Diseases and Related Health Problems
The ICD-10, the latest version of the International Statistical Classification of Diseases and Related Health Problems, classifies conversion disorder as a dissociative disorder. ICD-10 still includes somatization syndrome. Treatment
Psychotherapy, more specifically, cognitive behavioral therapy (CBT), is the most widely used form of treatment for somatic symptom disorder. In 2016, a randomized 12-week study suggested steady and significant improvement in health anxiety measures with cognitive behavioral therapy compared to the control group.CBT can help in some of the following ways:
Learn to reduce stress
Learn to cope with physical symptoms
Learn to deal with depression and other psychological issues
Improve quality of life
Reduce preoccupation with symptomMoreover, brief psychodynamic interpersonal psychotherapy (PIT) for patients with multisomatoform disorder has shown its long-term efficacy for improving the physical quality of life in patients with multiple, difficult-to-treat, medically unexplained symptoms.Antidepressant medication has also been used to treat some of the symptoms of depression, anxiety, and pain that are common among people who have somatic symptom disorder. Medications will not cure somatic symptom disorder, but can help the treatment process when combined with CBT. Controversy
Somatic symptom disorder has been a controversial diagnosis, since it was historically based primarily on negative criteria; that is, the absence of a medical explanation for the presenting physical complaints. Consequently, any person with a poorly understood illness can potentially fulfill the criteria for this psychiatric diagnosis, even if they exhibit no psychiatric symptoms in the conventional sense.
The following were conditions under the term Somatoform Disorders:

Conversion disorder: A somatic symptom disorder involving the actual loss of bodily function such as blindness, paralysis, and numbness due to excessive anxiety
Somatization disorder
Hypochondriasis
Body dysmorphic disorder: wherein the individual is concerned with body image, and the disorder is manifested as excessive concern about and preoccupation with a perceived defect of their physical appearance. Pain disorder
Undifferentiated somatic symptom disorder – only one unexplained symptom is required for at least six months.In the newest version of DSM-5 (2013) somatic symptom disorders are recognized under the term somatic symptom and related disorders:

Somatic symptom disorder: To replace many of what was formerly known as somatization disorders and hypochondriasis (hypochondria). Factitious disorder: Can be either imposed on oneself, or to someone else (formally known as factitious disorder by proxy). Illness anxiety disorder: A somatic symptom disorder involving persistent and excessive worry about developing a serious illness. This disorder has recently gone under review and has been altered into three different classifications. Somatoform disorder not otherwise specified (NOS)Included among these disorders are false pregnancy, psychogenic urinary retention, and mass psychogenic illness (so-called mass hysteria). Somatization disorder as a mental disorder was recognized in the DSM-IV-TR classification system, but in the latest version DSM-5, it was combined with undifferentiated somatoform disorder to become somatic symptom disorder, a diagnosis which no longer requires a specific number of somatic symptoms.