Final answer:
The client's persistent, excessive worry about their son's well-being for over a year, coupled with physical anxiety symptoms, point towards Generalized Anxiety Disorder (GAD), which is characterized by unrealistic or disproportionate worry not specific to situations.
Step-by-step explanation:
The findings that a nurse observes in a client, specifically the client's excessive worry about a catastrophic event involving a loved one (such as a son dying a horrible death) every day for over a year, along with physical symptoms of anxiety like pacing and hand-wringing, are most consistent with Generalized Anxiety Disorder (GAD). Unlike Panic Disorder or Acute Stress Disorder, which are characterized by episodes of intense fear or symptoms following a traumatic event, and unlike Posttraumatic Stress Disorder (PTSD), which results from severe psychological trauma, GAD involves persistent, excessive worry that is not confined to specific situations and is often unrealistic or out of proportion to the actual likelihood of the anticipated event.
Cognitive theories of GAD suggest these worries relate to an individual's perception and management of threats and uncertainty. GAD can significantly affect a person's daily life, and treatment options typically focus on managing symptoms through therapy, medication, or a combination thereof, as the causes of GAD often involve complex interactions between genetic and environmental factors.