The term “heart disease” covers several conditions affecting the heart and blood vessels, most commonly coronary artery disease (CAD), which often leads to heart attacks and strokes. Given the widespread nature of cardiovascular disease, people often wonder if it can be transmitted like a cold or the flu. The vast majority of heart disease cases, especially chronic forms driven by plaque buildup, are not contagious. Heart disease is classified by the World Health Organization (WHO) as a noncommunicable disease, meaning it is not passed from person to person through biological transmission methods.
The Direct Answer: Heart Disease is Not Transmissible
Chronic heart disease, particularly atherosclerosis (the hardening and narrowing of the arteries), results primarily from genetic predisposition and lifestyle factors. Atherosclerosis develops slowly over decades as fatty deposits, cholesterol, and other substances accumulate in the artery walls, forming plaques. This process is driven by internal metabolic conditions, not an external, transmissible agent.
The non-infectious drivers of this chronic condition are well-established risk factors internal to the individual’s physiology and habits. These include metabolic conditions such as high blood pressure (hypertension), elevated low-density lipoprotein (LDL) cholesterol, and diabetes. Lifestyle choices also play a role, including smoking, lack of physical activity, and diets high in saturated and trans fats.
A person’s family history may increase their risk, but this is not contagion. It reflects a shared genetic susceptibility to conditions like high cholesterol or hypertension, which create a favorable environment for plaque formation. The progressive development of atherosclerotic plaque is fundamentally a non-transmissible process stemming from physiological dysfunction and behavioral patterns.
Acute Infections That Directly Damage the Heart
Confusion about heart disease transmissibility often stems from acute conditions where an infection directly damages heart tissue. These are distinct from chronic atherosclerotic heart disease. The infection itself is contagious, but the resulting heart damage is a severe complication, not the primary illness being passed on.
One complication is myocarditis, which involves inflammation of the heart muscle (myocardium) and is often triggered by a viral infection. Viruses like influenza, coxsackievirus, and the virus causing COVID-19 can reach the heart. The immune system’s response may inadvertently damage the heart muscle cells, and this inflammation can weaken the heart’s ability to pump blood effectively.
Other infectious heart conditions include pericarditis (inflammation of the sac surrounding the heart) and endocarditis (an infection of the inner lining or valves). Endocarditis is usually caused by bacteria entering the bloodstream, often in people with pre-existing heart valve damage. Rheumatic fever, which can follow an untreated strep throat infection, is an example of how a contagious pathogen can lead to permanent heart valve damage and a non-contagious heart complication.
The Indirect Link: Chronic Infection and Systemic Inflammation
Modern research has uncovered an indirect link between chronic, low-grade infections and the progression of atherosclerosis, separate from acute infections that directly attack the heart. Atherosclerosis is a chronic inflammatory disease, and persistent infections contribute to systemic inflammation.
Chronic infections trigger the body’s immune response, leading to the continuous release of inflammatory molecules, such as cytokines, throughout the bloodstream. This prolonged systemic inflammation can damage the endothelium, the inner lining of the blood vessels. Damage to the endothelium is considered an initiating step in the formation of atherosclerotic plaque.
Specific persistent pathogens have been linked to an increased risk of cardiovascular events. These include the bacteria causing gum disease (periodontitis), certain herpes viruses like cytomegalovirus (CMV), and Helicobacter pylori (which causes stomach ulcers). While these infectious agents are transmissible, they do not directly pass heart disease. Instead, they act as chronic inflammatory stressors that accelerate the underlying, non-contagious atherosclerotic process. The presence of these microbes increases the overall inflammatory burden, which is an independent risk factor for plaque development and instability.
Shared Risk Factors vs. Biological Transmission
The perception that heart disease “runs in the family” is often a reflection of shared environmental and behavioral factors, rather than direct biological transmission. Families and communities frequently share the same dietary patterns, levels of physical activity, and exposure to environmental stressors. Children who grow up in a household where high-salt, high-fat foods are the norm, or where smoking is prevalent, are adopting risk factors that increase their chances of developing heart disease later in life.
This clustering of risk factors creates the appearance of transmissibility, but it is a consequence of shared habits and socioeconomic conditions. For example, a family history of high blood pressure might involve a genetic tendency, but it is often exacerbated by shared behaviors like consuming a high-sodium diet. The disease itself is not spread from person to person; rather, the conditions and behaviors that promote it are inadvertently passed down through cultural and lifestyle norms.