Understanding Heart Disease: Causes, Symptoms, Risk Factors and Prevention

Heart disease refers to a group of conditions that affect the heart and its ability to function properly. It forms part of the broader group of cardiovascular diseases (CVDs), which affect the heart and blood vessels.

 

Heart disease can develop gradually and may not always cause noticeable symptoms in its early stages. However, when left undetected or unmanaged, some forms of heart disease can lead to serious complications, including heart failure, heart attack and stroke.

 

Cardiovascular disease is a significant health concern across Southern Africa, as it is globally. In South Africa alone, an estimated 100,735 people died from cardiovascular disease in 2024.  Understanding the causes, risk factors and warning signs of heart disease can help people recognise potential problems earlier and take practical steps towards protecting their heart health.

 

What Is Heart Disease?

 

Heart disease is an umbrella term for conditions that affect the heart’s structure or function. There are several types of heart disease, including coronary heart disease, heart failure, heart valve disease, congenital heart disease, cardiomyopathy and hypertensive heart disease.

 

Some heart conditions are present from birth, while others develop over time as a result of factors such as high blood pressure, high cholesterol, diabetes, smoking, physical inactivity or an unhealthy diet. Some conditions can also have genetic or infectious causes.

 

Coronary heart disease, for example, develops when the arteries supplying blood to the heart become narrowed or blocked, often because fatty deposits build up inside the artery walls. This can reduce the amount of oxygen-rich blood reaching the heart muscle.

 

It is also important to distinguish heart disease from a heart attack. Heart disease describes an underlying condition affecting the heart, while a heart attack is an acute medical emergency that occurs when blood flow to part of the heart becomes blocked. A person can have heart disease without having a heart attack, although certain types of heart disease increase the risk of one.

 

What Causes Heart Disease?

 

There is no single cause of all heart disease. In many cases, several factors contribute to the development of cardiovascular disease over time.

 

For coronary heart disease, a major underlying process is atherosclerosis. This occurs when fatty deposits build up inside the arteries, causing them to become narrower and less flexible. If a blood clot forms over a narrowed area, it can suddenly block blood flow and cause a heart attack.

 

The biggest cause of heart disease therefore cannot be reduced to one factor. Rather, heart disease often results from a combination of modifiable risk factors, underlying health conditions, genetics and environmental influences.

 

The major behavioural contributors to cardiovascular disease include tobacco use, physical inactivity, an unhealthy diet and harmful use of alcohol. These can contribute to high blood pressure, high blood glucose, high cholesterol and overweight or obesity, which further increase cardiovascular risk.

 

Other conditions can have different causes. For example, rheumatic heart disease can damage the heart valves following rheumatic fever, while some forms of cardiomyopathy may have an inherited component. Congenital heart disease results from abnormalities in the structure of the heart that are present from birth.

 

What Are the Symptoms of Heart Disease?

 

The heart disease symptoms someone experiences depend on the type and severity of the condition. Some people may have no noticeable symptoms, particularly during the early stages.

 

Possible symptoms include:

 

• Chest pain, pressure, tightness or discomfort
• Shortness of breath
• Unusual tiredness or weakness
• Dizziness or light-headedness
• Fainting
• A rapid, irregular or pounding heartbeat
• Swelling in the legs, ankles or feet
• Reduced ability to exercise or becoming unusually breathless during physical activity

 

The early signs of heart disease are not always dramatic. A gradual reduction in exercise tolerance, persistent fatigue or breathlessness during activities that were previously manageable may warrant medical assessment, particularly when combined with other risk factors.

 

Coronary heart disease symptoms may include angina, which is typically experienced as pressure, heaviness, discomfort, aching or burning in the chest. The discomfort may also spread to the arms, shoulder, jaw, neck or back. Angina can sometimes be mistaken for indigestion or heartburn.

 

A heart attack can cause similar symptoms but requires emergency medical attention. Warning signs may include chest discomfort, pain spreading to the arm, shoulder, jaw or back, shortness of breath, nausea, sweating, light-headedness or fainting. Symptoms can vary between individuals, and women may be more likely to experience symptoms such as shortness of breath, nausea, vomiting or back and jaw pain.

 

If someone develops severe or persistent chest pain, difficulty breathing, fainting or other symptoms suggestive of a heart attack, they should seek emergency medical care immediately.

 

What Are the Risk Factors for Heart Disease?

 

Understanding the risk factors for heart disease is an important part of prevention. Some risk factors cannot be changed, while others can be managed through lifestyle changes and medical care.

Modifiable risk factors

 

These include:

 

• Smoking and other forms of tobacco use
• Physical inactivity
• An unhealthy diet
• Excessive salt intake
• High cholesterol
• High blood pressure
• Diabetes or high blood glucose
• Overweight or obesity
• Harmful alcohol use
• Poorly managed stress

 

These factors can interact with one another. For example, an unhealthy diet and physical inactivity can contribute to obesity, high blood pressure, diabetes and abnormal cholesterol levels, collectively increasing cardiovascular risk.

 

Non-modifiable risk factors

 

Age and family history can also influence a person’s risk. Having a close relative with cardiovascular disease may increase the likelihood of developing certain heart conditions. Some forms of heart disease are also linked to inherited genetic conditions.

 

However, having non-modifiable risk factors does not mean that heart disease is inevitable. Managing modifiable risks and attending appropriate health screenings can help reduce overall cardiovascular risk.

 

Is Hypertension the Same as Heart Disease?

 

Hypertension, or high blood pressure, is not the same as heart disease. Hypertension occurs when the pressure of blood against the walls of the arteries remains abnormally high. It is a separate condition, but an important risk factor for cardiovascular disease.

 

High blood pressure often produces no obvious symptoms, which means a person may have hypertension without knowing it. Regular blood pressure checks are therefore important. 

 

When hypertension remains uncontrolled, the heart has to work harder to pump blood around the body. Over time, this can place strain on the heart and blood vessels, increasing the risk of conditions such as coronary heart disease, heart failure, stroke and kidney disease. 

 

The signs and symptoms of hypertensive heart disease depend on how hypertension has affected the heart and whether complications have developed. A person may experience shortness of breath, chest discomfort, fatigue, palpitations or swelling in the legs, particularly if heart failure develops. However, hypertension itself may remain symptomless.

 

Heart Disease in Southern Africa

 

The burden of cardiovascular disease extends across Southern Africa and is influenced by changing lifestyles, urbanisation, ageing populations and the prevalence of conditions such as hypertension and diabetes.

 

The WHO African Region identifies high blood pressure as one of the most important cardiovascular risk factors in the region. Behavioural factors such as tobacco use, physical inactivity, unhealthy diets and harmful alcohol use also contribute significantly to cardiovascular risk.

 

South African data illustrate the scale of the problem. The World Heart Federation estimates that 100,735 people died from cardiovascular disease in South Africa in 2024. Its country data also report hypertension prevalence of 44.3% among women and 43.8% among men in 2019. 

 

These heart disease statistics in South Africa are a reminder that cardiovascular health requires attention at every stage of life. However, the broader Southern African context is equally important, as cardiovascular risk factors and access to prevention, screening and treatment vary across countries and communities.

 

Can Heart Disease Be Prevented?

 

Not every form of heart disease can be prevented. For example, congenital heart conditions and some inherited disorders cannot necessarily be avoided. However, many cardiovascular conditions can be prevented or their risk significantly reduced by addressing modifiable risk factors.

 

Knowing how to prevent heart disease starts with looking after the factors that can be changed.

 

1. Eat a heart-healthy diet

 

A balanced diet should include plenty of vegetables and fruit, whole grains, legumes, nuts, seeds and other minimally processed foods. Limiting foods high in saturated and trans fats, excess salt and added sugars can help support cardiovascular health.

 

It is also important to consider portion sizes and overall dietary patterns rather than focusing on a single food or nutrient.

 

2. Be physically active

 

Regular physical activity helps support a healthy weight and can improve blood pressure, cholesterol and blood glucose levels. Activities such as walking, cycling, swimming, dancing and strength training can all contribute to a more active lifestyle.

 

Adults should aim for regular moderate or vigorous physical activity, taking their existing health and fitness levels into account.

 

3. Don’t smoke

 

Tobacco use significantly increases cardiovascular risk. Stopping smoking can reduce this risk, and avoiding exposure to tobacco smoke is an important part of protecting heart health.

 

4. Manage blood pressure, cholesterol and blood glucose

 

Regular health checks can identify conditions such as hypertension, high cholesterol and diabetes before they cause noticeable symptoms. If medication is prescribed, taking it as directed and attending follow-up appointments can help manage these conditions and reduce cardiovascular risk. 

 

5. Maintain a healthy weight

 

Being overweight can increase the likelihood of developing conditions that contribute to cardiovascular disease. A sustainable approach to nutrition, physical activity and overall health is generally more beneficial than short-term restrictive diets.

 

6. Limit alcohol and manage stress

 

Harmful alcohol use can increase cardiovascular risk. Finding healthy ways to manage stress, getting adequate sleep and maintaining supportive social connections can also form part of a heart-healthy lifestyle.

 

The WHO recommends addressing behavioural and environmental risk factors such as tobacco use, unhealthy diet, physical inactivity, harmful alcohol use, obesity and air pollution as part of cardiovascular disease prevention. 

 

When Should You Seek Medical Care?

 

You should speak to a healthcare professional if you experience persistent or unexplained chest discomfort, shortness of breath, palpitations, dizziness, fainting, unusual fatigue or a noticeable reduction in your ability to exercise.

 

It is particularly important to have your cardiovascular risk assessed if you have high blood pressure, diabetes, high cholesterol, a family history of heart disease, smoke or use tobacco or have several cardiovascular risk factors.

 

Remember that the absence of symptoms does not necessarily mean that your heart is healthy. Some cardiovascular conditions remain silent until a serious event occurs. Early detection allows risk factors and diagnosed conditions to be managed before complications develop.

 

Conclusion

 

Heart disease encompasses a wide range of conditions, and its causes and symptoms can vary considerably. While some forms cannot be prevented, many of the factors that contribute to cardiovascular disease can be addressed through healthy lifestyle choices, regular health checks and appropriate medical treatment.

 

Knowing your blood pressure, cholesterol and blood glucose levels, staying physically active, eating a balanced diet, avoiding tobacco and seeking medical advice when symptoms arise can all contribute to better heart health.

 

For people living across Southern Africa, understanding cardiovascular risk and taking preventive action can be an important step towards reducing the burden of heart disease and protecting long-term health.

 

Frequently Asked Questions

 

• How is heart disease diagnosed?

Diagnosis depends on the suspected type of heart disease and may involve a medical history, physical examination, blood pressure measurement and blood tests. A healthcare professional may also recommend investigations such as an electrocardiogram (ECG), stress test or cardiac imaging. The appropriate tests depend on a person’s symptoms and individual risk factors.

 

• What lifestyle changes help prevent heart disease?

Eating a balanced diet, exercising regularly, avoiding tobacco, limiting harmful alcohol use, maintaining a healthy weight and managing blood pressure, cholesterol and blood glucose can all help reduce cardiovascular risk. Regular medical check-ups can also help identify and manage risk factors early.

 

• Is heart disease hereditary?

Some forms of heart disease have a genetic or hereditary component. A family history of cardiovascular disease can also increase a person’s risk. However, genetics is only one part of overall cardiovascular risk. Lifestyle and other health conditions and environmental factors can also play important roles.

 

• How does high blood pressure lead to heart disease?

Persistent high blood pressure places additional strain on the heart and blood vessels. Over time, it can contribute to changes in the heart muscle, damage to blood vessels and the development of conditions such as coronary heart disease and heart failure. Because hypertension often causes no symptoms, regular blood pressure checks are important. 

 

• What foods should I avoid to protect my heart?

Rather than focusing on completely avoiding individual foods, aim to limit foods that are high in saturated and trans fats, excessive salt and added sugars. Highly processed foods can also contribute significant amounts of salt, sugar and unhealthy fats to the diet. A varied diet based largely on vegetables, fruit, whole grains, legumes, nuts and other minimally processed foods is generally more supportive of cardiovascular health.

 

• When should I see a cardiologist?

You may be referred to a cardiologist if you have symptoms or test results suggesting a heart condition, or if you have significant cardiovascular risk factors that require specialist assessment. Seek emergency medical care rather than waiting for a cardiology appointment if you experience symptoms that could indicate a heart attack, such as severe or persistent chest pain, shortness of breath, sweating, fainting or pain spreading to the arm, jaw, shoulder or back.

 

• What are the different types of heart disease?

There are many types of heart disease, including coronary heart disease, heart failure, heart valve disease, congenital heart disease, cardiomyopathy and hypertensive heart disease. These conditions affect different parts or functions of the heart and may have different causes, symptoms and treatments.

 

• Can heart disease be reversed?

It depends on the type and extent of the heart disease. Some cardiovascular risk factors can be substantially improved through lifestyle changes and medical treatment, while some forms of established heart disease can be managed rather than completely reversed. Early detection and appropriate treatment can help prevent or delay complications and support better long-term heart health.

 

If you would like to get a general heart health screening, are experiencing any of the symptoms outlined above, or have a family history of heart disease, book a consultation with a Lenmed general practitioner or family physician who can guide you further.

 

For more information, please contact:

 

Dr T Ngale

Discipline: Physician (Internal Medicine)

Hospital: Kathu Private Hospital

Telephone: 064 702 8673

Email: [email protected]