What are the two leading causes of death? Heart disease and cancer explained

September 29, 2025 •

4 min read

For over half a century, heart disease and cancer have remained the two most significant public health challenges globally, and notably in the United States. The Centers for Disease Control and Prevention (CDC) consistently tracks these trends, providing crucial insights into what are the two leading causes of death and what can be done to combat them effectively.

Quick Summary

Heart disease and cancer are the two primary causes of death in many countries, including the U.S. Both conditions are influenced by a combination of genetics and modifiable lifestyle factors, such as diet and exercise. Understanding the shared and distinct risk factors for these major health concerns is key to prevention.

Key Points

Heart Disease vs. Cancer: Heart disease and cancer are the two leading causes of death, with heart disease often leading the list.
Lifestyle Impact: Many lifestyle factors, such as diet, exercise, and smoking, significantly influence the risk for both heart disease and cancer.
Genetic Influence: Family history and genetics play a role in risk, but most cases are linked to a combination of genetic and environmental factors.
Preventable Risks: Modifiable risk factors like tobacco use, excess weight, and high blood pressure are major targets for prevention strategies.
Early Detection: Regular health screenings and checkups are crucial for detecting both heart disease and cancer at their most treatable stages.
Public Health Efforts: National health agencies collect data to track mortality trends and inform public health decisions aimed at reducing the burden of these diseases.

A deeper look at the top mortality statistics

The most recent data from public health agencies like the CDC consistently shows that heart disease and cancer are the top two causes of death. While heart disease typically holds the number one spot, the gap between the two has narrowed over time due to advancements in treatment and shifting risk factors. Examining the nature, risk factors, and prevention methods for each provides a clearer understanding of this critical health issue.

Heart disease: Understanding the number one killer

Heart disease encompasses several cardiovascular conditions, most commonly coronary artery disease (CAD), which can lead to heart attacks. In CAD, the arteries supplying blood to the heart muscle become hardened and narrowed due to the buildup of plaque. This reduces blood flow, causing chest pain and potentially a heart attack if a blockage occurs.

Major contributing factors to heart disease

Unhealthy cholesterol levels: High levels of "bad" LDL cholesterol and low levels of "good" HDL cholesterol contribute significantly to plaque formation.
High blood pressure (hypertension): Elevated blood pressure puts extra strain on the heart and arteries, which can lead to weakened and damaged blood vessels over time.
Smoking: Tobacco use is a major risk factor, damaging blood vessels, increasing blood pressure, and reducing oxygen flow.
Diabetes: High blood sugar from diabetes can damage blood vessels and nerves that control the heart.
Physical inactivity and obesity: A sedentary lifestyle and excess weight increase the risk of hypertension, diabetes, and unhealthy cholesterol levels.
Uncontrolled stress: Chronic stress and anger have been shown to worsen heart disease and increase heart rate and blood pressure.
Genetics and family history: A history of heart disease in the family can increase your individual risk.

Cancer: The multifaceted threat

Cancer is not a single disease but a large group of diseases characterized by uncontrolled cell division and the potential to invade other parts of the body. A defining feature of cancer is the ability of these abnormal cells to ignore signals that typically tell cells to stop dividing or to die.

Common risk factors for various cancers

Tobacco use: Responsible for numerous cancer types, including lung, oral, and pancreatic cancers.
Excess body weight: Associated with a higher risk of breast, colon, pancreatic, and other cancers.
Alcohol consumption: Increases the risk of certain cancers, with higher consumption leading to a greater risk.
Poor diet: A diet lacking in fruits and vegetables and high in processed foods can contribute to cancer risk.
UV radiation: Exposure to ultraviolet rays from the sun or tanning beds is a primary cause of skin cancer.
Infections: Certain viruses and bacteria, such as HPV and Hepatitis B, can lead to specific cancers.
Genetics: Some hereditary genetic mutations significantly increase the risk of certain cancers, like BRCA mutations for breast cancer.

Comparative analysis: Heart disease versus cancer

While both conditions are linked to genetics and lifestyle, their progression and impact can differ. Early detection is crucial for both, but screening methods and treatments are distinct. Furthermore, while heart disease mortality has seen steady declines for decades, cancer mortality has also decreased, albeit with fluctuations, particularly for certain types. The ongoing rise in obesity and sedentary lifestyles, however, threatens to reverse some of these positive trends by increasing risk for both diseases.


Aspect	Heart Disease	Cancer
Core Mechanism	Compromised blood flow to the heart or brain due to vessel damage or blockage.	Uncontrolled proliferation of abnormal cells that invade tissue.
Primary Risk Drivers	High blood pressure, high cholesterol, smoking, poor diet.	Tobacco use, excess weight, alcohol consumption, infections, genetics.
Screening Examples	Blood pressure checks, cholesterol tests, stress tests.	Mammograms, colonoscopies, Pap tests, PSA tests.
Mortality Trends	Overall declining trend over past 50 years, but recently rising in some groups.	Declining trend for many cancers due to early detection and treatment.
Peak Age of Mortality	Highest mortality rates are among the elderly (85+).	Most fatal in middle age (60-64), before the dramatic rise in heart disease deaths.

Shared strategies for prevention

Many of the most powerful prevention strategies for heart disease and cancer overlap, allowing for a comprehensive approach to health. These include:

Maintaining a healthy weight: Obesity is a shared risk factor for many forms of both diseases.
Adopting a healthy diet: A plant-heavy diet rich in fruits, vegetables, and whole grains and low in saturated fats and processed foods benefits both cardiovascular health and cancer prevention.
Engaging in regular physical activity: Consistent exercise helps manage weight, lower blood pressure, and improve cardiovascular function, while also reducing the risk of several cancers.
Avoiding tobacco: This is the most critical preventative measure, with smoking being a leading cause for both major killers.
Managing stress: Chronic stress affects heart health directly and can also influence risk factors related to cancer.

For more detailed information on living a heart-healthy life, you can explore the resources provided by the American Heart Association at https://www.heart.org/en/healthy-living.

The crucial role of public health and individual action

While genetic predisposition plays a role, a significant portion of the risk for heart disease and cancer is influenced by modifiable lifestyle factors. Public health initiatives focus on raising awareness and promoting screenings, but individual action remains paramount. The data shows that small, consistent changes can yield substantial benefits over time. By being proactive and informed, individuals can take control of their health, reducing their risk of falling victim to these two persistent threats and contributing to a healthier society as a whole.

Frequently Asked Questions

The number one leading cause of death is typically heart disease, particularly coronary artery disease, which is a leading cause of heart attacks.

While cancer is a broad category, the most common causes of cancer death include lung, colorectal, pancreatic, and breast cancers, though prevalence varies by gender and other factors.

Yes, heart disease and cancer share many common risk factors, such as obesity, diabetes, and smoking. There is also growing evidence of biological links between the two conditions.

While not all cases are preventable, a significant portion can be avoided or delayed by managing controllable risk factors like diet, physical activity, and avoiding tobacco and excessive alcohol.

A healthy diet is extremely important, as it helps manage weight, cholesterol, and blood pressure, all of which are key risk factors for both heart disease and many cancers.

Yes, regular physical activity is a powerful tool for prevention. It helps maintain a healthy weight and lowers the risk of many chronic diseases, including heart disease and certain cancers.

Knowing the leading causes of death helps individuals prioritize health decisions and encourages public health officials to focus on targeted interventions and prevention programs that can save lives and improve overall health.