Which of the following is a hallmark symptom of peptic ulcer disease?

Loss of appetite is a hallmark symptom of peptic ulcer disease because it can be indicative of the discomfort and pain associated with ulcers in the stomach or the duodenum. When a patient has peptic ulcers, the pain typically occurs after eating or is aggravated by meals, which can lead to the avoidance of food. This discomfort often manifests as a decrease in the desire to eat, therefore altering normal eating habits and contributing to weight loss in some cases.

While other symptoms like fatigue or chest tightness may be associated with various gastrointestinal issues or other conditions, they are not specific to peptic ulcer disease. Excessive salivation is not commonly linked to ulcers, and when considering the direct association of symptoms with peptic ulcers, loss of appetite clearly stands out as a significant and consistent indicator of the disease.