Angina pectoris is the medical term for chest pain or discomfort caused by reduced blood flow to the heart muscle. It is one of the most important symptoms in cardiology — a direct warning that the heart is not receiving sufficient oxygen, most commonly because of narrowed coronary arteries. Angina is a symptom of underlying coronary artery disease (CAD), not a disease in itself, and its significance lies in what it says about your heart's blood supply.
Understanding which type of angina you have — and when it becomes an emergency — is clinically critical.
The Three Types of Angina Pectoris
Angina is classified by its cause, pattern, and clinical urgency. The distinction between stable and unstable angina is one of the most important in emergency medicine.
- Stable Angina: The most common form. Caused by fixed atherosclerotic plaques narrowing the coronary arteries. Symptoms are predictable — typically triggered by physical exertion, emotional stress, cold weather, or a heavy meal — and usually resolve within 5 minutes of rest or after taking a GTN spray or tablet. While stable angina is not immediately life-threatening, it is a serious warning sign of underlying coronary artery disease that requires investigation and management to reduce the risk of heart attack.
- Unstable Angina: Unstable angina is caused by a ruptured or eroded coronary artery plaque with partial clot formation, acutely reducing blood flow. Symptoms occur at rest or with minimal exertion, are more severe, last longer (20 minutes or more), and do not reliably resolve with rest or GTN. Unstable angina is classified as Acute Coronary Syndrome (ACS) and is a medical emergency.
- Variant Angina: Variant angina is caused by temporary spasm of a coronary artery rather than fixed plaque obstruction. It occurs in cycles, typically at rest and often during early morning hours, and typically responds to calcium channel blockers or nitrates. It can occur in people without significant coronary artery disease.
Is it Angina or a Heart Attack?
Angina and a heart attack share similar symptoms — and patients frequently cannot tell them apart without medical assessment. The key clinical distinction is whether the reduced blood flow is temporary and reversible (angina) or complete and persistent (heart attack, causing irreversible heart muscle damage).
If you are unsure whether you are experiencing angina or a heart attack — call 995. The consequences of delaying treatment for a heart attack are irreversible. The consequences of arriving at hospital with stable angina that resolves are minimal.
Symptoms of Angina Pectoris
The symptoms of angina depend on the type and the individual patient. Women, in particular, are more likely to present with atypical symptoms that can delay diagnosis.
Classic symptoms
- Chest pain, pressure, tightness, squeezing, heaviness, or fullness — typically in the centre or left side of the chest
- Pain or discomfort radiating to the left arm, both arms, jaw, neck, shoulder, or upper back
- Symptoms typically triggered by exertion, cold air, a heavy meal, emotional stress, or sexual activity (stable angina)
- Symptoms that begin at rest or wake the patient from sleep (unstable or variant angina)
- Symptoms lasting 2–5 minutes with stable angina; 20 minutes or longer with unstable angina
Associated Symptoms
- Breathlessness — occurring with or without chest pain
- Fatigue — disproportionate tiredness with exertion
- Nausea or vomiting
- Sweating — cold sweat or diaphoresis
- Dizziness or lightheadedness
- Palpitations — awareness of irregular or rapid heartbeat
Atypical symptoms — more common in women
Women with coronary artery disease are significantly more likely than men to experience angina without classic chest pain. Symptoms that may represent angina in women include:
- Upper abdominal discomfort, bloating, or indigestion — particularly on exertion
- Jaw pain or toothache — especially with exercise
- Back pain or shoulder pain without clear musculoskeletal cause
- Unexplained fatigue or reduced exercise tolerance
- Breathlessness on minimal exertion without chest symptoms
These atypical presentations are the most common reason cardiac disease is delayed in women. If any of these symptoms occur with exertion and resolve with rest — or if they occur at rest — a cardiac assessment is warranted.
What Causes Angina?
The primary cause of angina is coronary artery disease (CAD) — narrowing of one or more of the coronary arteries that supply blood to the heart muscle, caused by the buildup of atherosclerotic plaque inside the arterial wall.
The coronary arteries supply oxygen-rich blood to the myocardium (heart muscle). At rest, a moderately narrowed artery may supply sufficient blood flow to meet the heart's needs without triggering symptoms. During exertion — when the heart beats faster and requires more oxygen — the narrowed artery cannot increase flow proportionally, and the area of muscle supplied becomes temporarily oxygen-deficient. This ischaemia produces the sensation of angina.
In unstable angina, the narrowing is not fixed by stable plaque but by a ruptured plaque with superimposed clot formation — reducing flow acutely and unpredictably. In variant angina, no fixed plaque is involved; temporary spasm of the coronary artery itself reduces flow.
Risk factors for coronary artery disease and angina
- Age: Your risk increases significantly in men over 45 and women over 55
- Family history: First-degree relative with heart disease before age 60
- Smoking: Directly damages arterial walls and accelerates atherosclerosis
- Hypertension: Elevated blood pressure damages the coronary endothelium and accelerates plaque formation
- Diabetes: Insulin resistance and hyperglycaemia are independently associated with accelerated atherosclerosis
- High cholesterol: Elevated LDL cholesterol is a primary driver of atherosclerotic plaque
- Obesity: Particularly central obesity
- Physical inactivity: Sedentary lifestyle is an independent risk factor
- Psychological stress: Chronic stress elevates cortisol and catecholamines, worsening cardiovascular risk
How do you prevent Angina Pectoris (Chest Pain)?
You can prevent angina pectoris by making lifestyle changes such as:
- Limiting alcohol consumption
- Quit smoking
- Eat a healthy diet
- Exercise regularly
- Manage health conditions
- Properly manage stress
How is Angina Diagnosed?
Diagnosis begins with a careful clinical history — the character, location, radiation, duration, and triggers of chest pain are the most diagnostically informative elements. A range of investigations then confirms the diagnosis and characterises the severity of underlying coronary artery disease.
- Electrocardiogram (ECG): Records the heart's electrical activity. A resting ECG may be normal in stable angina between episodes. An ECG during symptoms may show ischaemic changes. Essential first investigation for any chest pain.
- Blood tests: Troponin to detect heart muscle damage (elevated in heart attack, not in stable angina). Lipid panel, fasting glucose, HbA1c, kidney function, and full blood count to identify risk factors and contributing conditions.
- Echocardiogram: Ultrasound of the heart assessing chamber size, wall motion, valve function, and ejection fraction. Identifies areas of reduced wall motion from previous ischaemia or infarction.
- Exercise Stress Test: ECG monitoring during graded treadmill exercise. Identifies exercise-provoked ischaemia through ECG changes, symptoms, and haemodynamic response. Used to stratify risk and assess functional capacity in stable angina.
- CT Coronary Angiogram: Non-invasive CT imaging of the coronary arteries, identifying atherosclerotic plaque, calcification (CT calcium score), and arterial stenosis. Provides anatomical detail of coronary artery disease without catheterisation. The preferred first-line advanced investigation for stable chest pain in most patients.
- Conventional Coronary Angiogram: Catheter-based imaging of the coronary arteries via a small puncture at the wrist (radial) or groin (femoral). The gold standard for coronary anatomy. Used when CTCA suggests significant stenosis warranting intervention, or when clinical presentation requires direct assessment. Allows immediate PCI if a significant blockage is identified.
- Intravascular Imaging: Functional pressure measurement (FFR — fractional flow reserve) and intravascular imaging assess whether a coronary stenosis is causing significant ischaemia and guides the need for stenting. Used at the time of conventional angiography for borderline lesions.
- Myocardial Perfusion Imaging: Nuclear medicine or MRI-based imaging showing blood flow to different regions of the heart muscle at rest and with stress. Identifies areas of ischaemia and scar tissue. Used when CTCA is not suitable or for further characterisation.
- Holter Monitor: Continuous 24–48 hour ECG recording worn as an outpatient device. Identifies transient arrhythmias or ischaemic changes during daily activity, including nocturnal variant angina episodes.
