Final answer:
The main clinical factor of hypochondriasis is excessive worry or fear of having a serious medical condition, while somatization disorder is characterized by recurrent, multiple physical symptoms that cannot be explained by a known medical condition.
Step-by-step explanation:
The main clinical factor of hypochondriasis is excessive worry or fear of having a serious medical condition, despite having little or no medical evidence to support the belief. People with hypochondriasis may interpret normal bodily sensations as signs of a serious illness. On the other hand, somatization disorder is characterized by recurrent, multiple physical symptoms that cannot be explained by a known medical condition. These symptoms often cause significant distress and impairment in daily functioning. Unlike hypochondriasis, somatization disorder involves the presence of actual physical symptoms, but without a clear organic cause.