Which of these is a symptom of unstable angina?

Severe chest pain is a classic symptom of unstable angina, which is a type of acute coronary syndrome characterized by unpredictable and worsening symptoms. Unlike stable angina, which is typically triggered by exertion and relieved by rest, unstable angina may occur at rest or with minimal exertion and can represent a critical state where the heart is not receiving enough blood supply due to plaque rupture or thrombosis in the coronary arteries.

Patients often describe the pain associated with unstable angina as more intense and persistent compared to episodes experienced with stable angina. This severity and unpredictability can lead to a sense of urgency for medical evaluation, as it signals the need for immediate intervention to prevent progression to a myocardial infarction (heart attack).

Symptoms such as sudden weight gain, headaches, and abdominal pain are not characteristic of unstable angina. Sudden weight gain could be a sign of fluid retention or other medical conditions, headaches may be due to a variety of non-cardiac causes, and abdominal pain could arise from numerous gastrointestinal or other issues unrelated to cardiac events. Therefore, severe chest pain stands out as the primary and defining symptom indicative of unstable angina.