20 years old female with complaints of nausea, vomiting, dizziness and pain in the legs. Her physical examination and all lab investigations and radiological investigations are normal. What would be the most probable diagnosis?

Here the patient presents with multiple, medically unexplained symptoms (MUS). This is an example of Somatisation Disorder. In somatoform pain disorder the major symptom will be unexplained chronic pain, which is usually isolated. Patients have a long history of complaints of severe pain out of propoion to any biomedical findings that are present. Exacerbations and remission of complaints correlate with psychogenic factorsThe term somatization refers to the experience and repoing of physical symptoms that cause distress but lack a corresponding level of tissue damage or pathology and are linked to psychosocial stress. In contrast to this broad and inclusive view of the process, psychiatrists have developed strict diagnostic criteria that define several distinct disorders, which are collectively referred to as the somatoform disorders. As such, clinicians should be careful to distinguish between somatization, as defined above, and somatization disorder, which is one type of somatoform disorder. In general, these conditions are chronic and reflect an enduring way for the affected individuals to cope with psychosocial stressors. Ref: Shim J., Eisendrath S.J. (2008). Chapter 25. Somatization. In M.D. Feldman, J.F. Christensen (Eds), Behavioral Medicine: A Guide for Clinical Practice, 3e.