What is a common symptom of unstable angina?

Unstable angina is characterized by unexpected chest pain, which can occur at rest or with minimal exertion, signifying that the condition is deteriorating. The pain is often more severe, prolonged, and can occur at any time without clear triggers, distinguishing it from stable angina, which typically occurs with predictable levels of exertion.

The symptom of pain at rest is particularly critical because it reflects a change in the pattern of angina that may indicate a significant increase in cardiac risk. This resting pain is alarming because it suggests that the heart is not receiving sufficient blood flow, which could lead to a heart attack if not addressed promptly. Recognizing this symptom in patients is crucial for timely intervention.

Other options do not align as clearly with the defining characteristics of unstable angina. Chest pain during exercise relates more to stable angina, stabbing back pain is not a typical symptom of angina in general, and chronic fatigue is often more associated with other cardiovascular conditions rather than a specific indicator of unstable angina.