How can Ms. Littleton's problem, characterized by excessive worry about having a serious illness despite negative physical tests, best be identified?

The correct identification for Ms. Littleton's problem is related to hypochondriasis, which is characterized by an excessive preoccupation with having a serious illness despite the absence of any medical evidence to support such concerns. Individuals with hypochondriasis often interpret normal bodily functions or minor symptoms as signs of severe medical conditions. This aligns perfectly with Ms. Littleton's situation, where she exhibits excessive worry about having a serious illness even when physical tests indicate otherwise.

Understanding this condition involves recognizing that it is not merely the fear or anxiety about health, but rather a persistent belief in having a medical condition that is not substantiated by medical evaluation. This distinguishes hypochondriasis from other anxiety disorders where the symptoms and concerns may differ in nature and focus. For instance, generalized anxiety disorder encompasses broader worries about various aspects of life, while panic disorder is characterized by sudden and intense bouts of fear that may lead to panic attacks. Somatic symptom disorder also involves physical symptoms, but the primary concern is the experience of these symptoms rather than an unfounded fear of a serious illness.