Angina, also known as angina pectoris, is a symptom of coronary artery disease (CAD). It is characterized by chest pain or discomfort due to reduced blood flow to the heart muscle. Here's an overview covering symptoms, epidemiology, causes, diagnosis, treatment, and prevention:

Overview:

Angina occurs when the heart muscles are starved of oxygen because the coronary arteries, which supply blood to them, have become narrow or clogged. The lack of enough oxygen in the heart muscle leads to chest pain or discomfort. Physical exertion or emotional stress usually triggers angina that can be relieved by rest and medication.

Symptoms:

• Chest pain or discomfort, typically described as pressure, tightness, squeezing, or aching
• Pain may radiate to the neck, jaw, shoulders, arms (usually the left arm), back, or upper abdomen
• Shortness of breath
• Fatigue
• Nausea
• Sweating
• Dizziness or lightheadedness

Epidemiology:

• Angina is a common symptom associated with CAD that afflicts millions worldwide
• Aging increases the prevalence rate of angina that affects more men than women.
• Risk factors such as smoking, hypertension, hyperlipidemia, diabetes mellitus, obesity and a sedentary lifestyle increase an individual’s chance of developing angina and CAD.

Causes:

• Coronary artery disease (CAD): The most frequent cause for angina is obstructive CAD where atherosclerosis narrows down or blocks off blood vessels leading to reduced blood flow to the heart.
• Other causes include: Angina could also be caused due to other conditions such as spasmatic constriction of coronary arteries spasm, dissection of coronary arteries, microvascular disease (small vessel disease) or other forms of heart diseases such as aortic stenosis and hypertrophic cardiomyopathy.

Diagnosis:

• Medical history and physical examination: Your doctor will need to know about your symptoms, medical history, risk factors and do a physical examination by listening to your heart beat and looking for signs of CAD.
• Diagnostic tests: Tests such as electrocardiogram (ECG/EKG), stress test, echocardiogram, coronary angiography, CT angiography or cardiac MRI may be done in order to assess heart function, blood flow and find out about blockages in the coronary arteries.

Treatment:

Lifestyle modifications: Changes in the lifestyle like quitting tobacco smoking; embracing a diet that is healthy for the heart which should have low amounts of saturated fats , cholesterol and sodium; regular exercise routines; maintaining a healthy body weight and proper management of stress can help lower the risk of angina pectoris and CAD.

Medications:

• Nitroglycerin: Nitroglycerin tablets or sprays can relieve episodes of angina acutely by dilating the coronary arteries so that blood flows easily around the heart.
• Antiplatelet Medications: Aspirin or clopidogrel might be prescribed to hinder blood clots formation thus reducing the chances of contracting a heart attack.
• Beta-blockers, calcium channel blockers, ACE inhibitors or statins could be prescribed to decrease chest pain, lower blood pressure and enhance cardiac performance.

Revascularization procedures: In cases of severe CAD, procedures such as angioplasty with stent placement or coronary artery bypass surgery (CABG) may be performed to restore blood flow to the heart muscle and relieve symptoms.

Prevention:

Regular medical follow-up: Routine visits with a healthcare provider are essential in monitoring overall heart health, tracking any risks that may come up and adjusting treatment as required.