When should you call 911 for someone experiencing angina?

Calling 911 when someone is experiencing angina is critical if chest pain persists for five minutes after administering the first dose of nitrates. This is because angina may signify underlying coronary artery disease, and the continued presence of pain could indicate that the condition is worsening, possibly leading to a heart attack. Nitrates are expected to relieve angina pain, typically within a few minutes; hence, failing to achieve relief suggests the need for immediate medical evaluation and potential intervention.

In contrast, if the person feels better after the first dose of nitrates, it's a sign that the angina may have been temporary or less severe, so there's typically no need for an emergency call. Feeling relieved by rest also suggests that the angina is stable and does not usually warrant immediate medical attention. Numbness in the arms can be concerning and could indicate a more significant issue, but it alone is not an established reason to call for emergency assistance unless accompanied by persistent pain.