Unstable angina and blood pressure: what to know

Unstable angina is a change in heart-related chest discomfort caused by reduced blood flow to the heart muscle. Blood pressure may be high, low, or within a usual range during an episode. Pain, fear, exertion, and other illness can temporarily alter a reading, while some blood-pressure medicines can lower it. The number is therefore one part of the assessment, not a diagnosis.

A clinician may ask when the discomfort started, whether it occurs at rest, how long it lasts, and whether it is becoming more frequent or harder to settle. An electrocardiogram and blood tests may be used to look for heart injury or reduced blood flow. [Angina](/conditions/angina/) and [Hypertension](/conditions/hypertension/) are related topics, but they are not interchangeable diagnoses.

If a new or changing chest symptom is happening, stop activity, sit upright, and arrange urgent medical help. Do not drive yourself if symptoms are severe or ongoing. Take prescribed heart medicines only as directed; do not take an extra dose of blood-pressure medicine to correct a home reading unless a clinician has specifically instructed you.

Bring a list of medicines, allergies, and recent blood-pressure readings. Assessment may include an [Electrocardiogram](/treatments/diagnostics-and-screening/ecg/) and a treatment plan that could involve [Blood Pressure Medication](/treatments/medical-management/blood-pressure-medication/) or other heart medicines.

Call emergency services immediately for chest pressure, squeezing, or tightness that is severe, new, worsening, occurs at rest, or does not settle promptly. Seek the same urgent help if it comes with breathlessness, sweating, nausea, faintness, unusual weakness, or discomfort spreading to the arm, back, neck, or jaw. A [Chest Tightness](/symptoms/chest-tightness/) page can help explain the symptom, but it should not delay emergency assessment.

Ask: What do my blood-pressure readings mean in this episode? Which symptoms should prompt emergency help? Which medicines should I take or avoid? Do I need an electrocardiogram, observation, or cardiology review?