Which of the following best describes unstable angina symptoms?

The symptoms of unstable angina are characterized by their unpredictable nature and can indeed gradually increase in severity over time. Unlike stable angina, which is often triggered by consistent factors such as physical exertion or emotional stress and tends to resolve predictably with rest or medication, unstable angina can manifest without clear triggers and may occur at rest, while sleeping, or with minimal exertion.

Patients may report episodes that last longer than typical anginal episodes, or may describe a change in their usual pattern of angina—whether it becomes more frequent, more severe, or lasts longer than they have previously experienced. This progression in symptoms represents a significant shift toward more serious underlying cardiovascular conditions, raising the urgency for medical evaluation and intervention.

The other options do not accurately reflect the nature of unstable angina. Symptoms that only occur during physical activity or solely during sleep do not encompass the variability of unstable angina, and the notion of predictable and short-lived symptoms conflicts with the potential for increasing severity and the unpredictability typical of unstable angina episodes.