Definition of Somatoform Disorders:

The term 'Somatoform Disorders' was introduced in the scientific literature by the American Psychiatric Association in the  third edition of its Diagnostic and Statistical Manual of Mental Disorders (DSM 111). Though some of the disorders included in the group are known since centuries. It was included in  ICD-10 in 1992. The various disorders included in the group have the central characteristic of having. physical symptom without organic basis as the presenting feature. The physical symptoms suggest a physical illness (hence somatoform) for which there are no demonstrable organic findings or known physiologic factors or  conflicts. 

Definition:

Somatoform Disorders are reflected in physiological complaints or symptoms,  are not under voluntary control and do not demonstrate organic findings. Faan and Goshan (1997) state "the patient converts histher psychological distress into complaints pertaining to different parts of  the body (for example, complaining of palpitation or pain instead of fear)