Coronary Artery Disease (CAD): Causes, Symptoms and Stages

The heart has its own network of blood vessels. These coronary arteries deliver the oxygen and nutrients the heart muscle needs to keep pumping. When blood flow through them becomes restricted, the muscle may struggle to get enough oxygen, particularly during physical activity.

A narrowing does not always cause immediate symptoms. At rest, the heart may still receive enough blood. The problem can become apparent when someone walks uphill, climbs several flights of stairs, or does anything else that makes the heart work harder. Chest discomfort may then appear and ease after the activity stops.

There is another possibility. A plaque can rupture, prompting a blood clot to form at the affected site. If the clot blocks blood flow, the heart muscle supplied by that artery may be injured. This is one way a heart attack occurs.

Coronary artery disease usually develops when fatty deposits, called plaques, build up inside the coronary arteries. These deposits contain cholesterol, fat, calcium and other substances. Over time, they can make the arteries narrower and leave less room for blood to pass through.

The process is known as atherosclerosis. It often begins years before a person notices any symptoms.

Several changes in the body can contribute to plaque formation:

• Excess LDL cholesterol can collect in artery walls and contribute to plaque build-up.
• High blood pressure, smoking and high blood sugar can damage the inner surface of blood vessels.
• Inflammatory processes play a role in plaque development and can affect how stable a plaque remains.
• A plaque can crack or rupture, allowing a blood clot to form at the site. If the clot suddenly blocks blood flow, it can cause a heart attack.

CAD does not always progress at the same rate. In some people, the arteries narrow gradually. In others, a previously stable plaque becomes unstable and causes a sudden blockage. This is one reason a person may experience a heart attack without having recognised warning signs beforehand.

Some CAD risk factors are linked to daily habits, while others cannot be changed. Having one risk factor does not mean someone will definitely develop other serious coronary artery disease. The concern generally increases when several factors occur together.

Managing blood pressure, cholesterol and diabetes, avoiding tobacco, staying active and following a balanced diet can help reduce risk.

A person can also develop CAD without having an obvious risk factor. If symptoms suggest a heart problem, they should be assessed even if they are young, physically active or have no known history of heart disease.

Coronary artery disease does not progress at the same rate in everyone. One proposed system groups the condition into four stages, from 0 to 3, based on how much plaque has built up in the coronary arteries. Doctors can measure this using coronary CT angiography (CCTA). The system is still being studied and is not routinely used in clinical practice.

Coronary artery disease symptoms depend on how severely blood flow is affected and whether the problem develops gradually or suddenly. Some changes can be easy to dismiss, especially when they settle after a few minutes of rest.

Common symptoms include:

• Chest discomfort: Pain, pressure, squeezing or heaviness in the chest, sometimes described as indigestion.
• Shortness of breath: Feeling breathless during activities that were previously manageable, or sometimes while resting.
• Pain in other areas: Discomfort may spread to one or both arms, the shoulders, back, neck, jaw or upper abdomen.
• Unusual fatigue: Everyday activities may leave a person more exhausted than expected.
• Dizziness or light-headedness: This can occur alongside other symptoms, although it has many possible causes.
• Nausea or sweating: These may accompany chest discomfort, particularly during a heart attack.

A heart attack does not always cause severe or unmistakable pain. Some people experience pressure or discomfort that feels mild at first.

Call your local emergency number immediately if chest discomfort is new, severe, persistent or accompanied by symptoms such as breathlessness, cold sweating, nausea, faintness or pain spreading to the arm, back, neck or jaw. Do not wait to see whether it goes away, and do not drive yourself to hospital.

A few distinctions may help explain why the symptoms need attention:

• Possible stable angina: Discomfort follows a familiar pattern, often during exertion, and eases with rest. It still needs medical assessment and treatment.
• Possible unstable angina or heart attack: Pain occurs at rest, feels different from usual, becomes more frequent or severe, or does not settle as expected. This requires an emergency assessment.
• Possible non-cardiac pain: Acid reflux, muscle strain and other conditions can also cause chest discomfort. However, it is not safe to assume that chest pain has a harmless cause without appropriate assessment.

If a person has been prescribed medicine for angina, they should follow their clinician's instructions. They should not delay emergency help while trying repeated home remedies or waiting for symptoms to pass.

A doctor will usually start by asking when the symptoms occur. For instance, does the chest feel tight after walking for a few minutes? Does the discomfort go away with rest? Has it started happening more often than before?

They will also ask about existing health problems, smoking, family history and medicines the person takes. Blood pressure and cholesterol levels matter, too. No single test tells the whole story, so the doctor may recommend further investigations.

A thin tube is guided into a blood vessel and contrast dye is used to show the coronary arteries on X-ray. Doctors may recommend it when they need a closer look at a suspected blockage or are planning treatment.

Not everyone needs all these tests. A person with symptoms that suggest a heart attack needs urgent assessment, usually including an ECG and blood tests. Someone with symptoms that develop gradually may have time for planned testing.

Once the results are available, the doctor can judge how serious the problem is and discuss the next steps. That might mean medication and regular monitoring. If the narrowing is more severe or symptoms are difficult to control, a procedure may also be considered.

Finding out that a coronary artery is narrowed does not automatically mean surgery is needed. Some people manage the condition with medicines and changes to their daily routine. Others need a procedure to improve blood flow. It depends on the arteries affected, the symptoms and the person's overall health.

Small, consistent changes can help reduce the strain on the heart. Someone who smokes, for example, can lower their cardiovascular risk by quitting. Food choices matter as well. Eating more vegetables, fruit, whole grains, beans, lentils and nuts, while cutting back on foods high in saturated fat and excess salt, can help improve heart health.

Movement is important, too, but a person with diagnosed CAD should check with their doctor before starting a demanding exercise routine. The right level of activity depends on their condition. Keeping blood pressure, cholesterol and blood glucose under control is another key part of coronary artery disease treatment.

A diagnosis of coronary artery disease does not automatically qualify someone for a critical illness insurance payout. The insurer looks at the condition covered by the policy and whether the medical evidence meets its requirements.

Start with the illnesses listed in the policy. If you are concerned about CAD, look for its specific definition. A policy that covers heart attacks may not cover an earlier diagnosis of narrowed coronary arteries. The same applies to angioplasty and bypass surgery, which may have different terms.

Also check the following:

• Pre-existing conditions: Find out how the insurer treats an existing CAD diagnosis.
• Exclusions: Read the circumstances in which a claim will not be paid.
• Waiting and survival periods: Check how long you must wait for cover and whether a survival requirement applies.
• Claim requirements: Find out which medical reports and records you will need.
• Benefit amount: Confirm the payout for an accepted claim and whether making a claim affects any other benefits.

Answer the insurer's medical questions accurately. If a clause is unclear, ask for clarification in writing before purchasing the policy.

Coronary artery disease can develop gradually, and some people have no symptoms until the condition becomes serious. Recognising possible warning signs, getting medical advice and managing risk factors can help reduce the chance of complications.

If you are choosing critical illness insurance, check the exact conditions covered. CAD, a heart attack and procedures such as angioplasty or bypass surgery are not necessarily treated as the same claim event.

Disclaimer: The information provided in this article is for general informational and educational purposes only and should not be construed as medical advice, diagnosis, treatment recommendation, or professional healthcare guidance. Treatment costs mentioned are indicative and may vary based on factors such as the patient's medical condition, hospital, city, surgeon's expertise, room category, and other treatment-related requirements. Readers are advised to consult qualified healthcare professionals and obtain cost estimates directly from healthcare providers before making any medical or financial decisions. Axis Max Life Insurance does not provide medical services, endorse any specific healthcare provider.