By Shamard Charles, MD, MPH 

 Medically reviewed by Richard N. Fogoros, MD

An enlarged heart can lead to serious health problems such as heart failure, stroke, or even sudden death. The condition is also known as cardiomegaly.

Your heart can become enlarged when it has to work harder as a result of stress, infection, or heart disease. The heart is usually the size of a fist, but it has the ability to grow in response to the demands that are placed on it, as is the case during pregnancy, strenuous exercise, and when you have a heart condition.

This article reviews the symptoms of an enlarged heart. It also looks at the potential complications of an enlarged heart, how the condition is treated, and when you should see a healthcare provider.

Verywell / Jessica Olah

What Is an Enlarged Heart?

Cardiomegaly describes a heart that is a larger size than what is typical. It can happen to parts of the heart or the entire heart. 

Your heart may become enlarged if you have a condition that puts it under a lot of stress. The condition can be temporary, such as in pregnancy, or permanent, which can happen with certain medical conditions. 

What Are the Symptoms of an Enlarged Heart?

Symptoms of an enlarged heart are largely predicated on the root cause. Symptoms vary widely because an enlarged heart may be the result of various causes.

Frequent Symptoms

Some of the most common symptoms of an enlarged heart include:1

• Shortness of breath on exertion or rest, orthopnea, and paroxysmal nocturnal dyspnea

• Swelling, also known as edema, of the hands, feet, and abdomen

• Fatigue or extreme tiredness

• Poor exercise tolerance

• Heart palpitations

• Lightheadedness

• Syncope or fainting

• Chest pain (angina)

• Nausea

• Early satiety (feeling full after eating just a little)

Rare Symptoms

Symptoms of an enlarged heart are not always noticeable or may be mistakenly attributed to other medical conditions. Some rare symptoms may be associated with an enlarged heart, especially if the condition worsens and heart failure ensues, including:

• Shortness of breath when lying down (orthopnea)

• Coughing, especially when lying down

• New arrhythmias or heartbeat irregularities

• Abdominal bloating

• Chest pain or pain in the arms and legs due to blood clots

What Causes an Enlarged Heart?

Any disease that makes the heart work harder can cause an enlarged heart. Diseases that are commonly associated with an enlarged heart include:

• Anemia

• Arrhythmia

• Cardiomyopathy

• Congenital heart disease

• Coronary artery disease

• Heart valve disease

• Thyroid disease1

You can also develop an enlarged heart if you regularly consume large amounts of alcohol or if you smoke. A family history of enlarged heart and a sedentary lifestyle can also play a role.

What Are the Complications of an Enlarged Heart?

A damaged heart muscle can lead to stagnated blood flow, arrhythmias, and even death.

Complications are most often due to dilated cardiomyopathy, a thinning of the ventricle walls that leads to an enlarged heart. The ventricles generate most of the pumping force of the heart. When these lower chambers lose their ability to contract, they are unable to pump enough blood to meet the body's needs, which can result in the following:

• Blood clots: People with cardiomegaly are at risk of blood clots because blood flow becomes stagnated. Blood clots that enter the bloodstream not only impede blood flow but may also put you at higher risk of heart attack or stroke, especially if you have a higher risk of cardiovascular complications such as a history of diabetes, high blood pressure, or coronary artery disease.

• Cardiac arrest and sudden death: An enlarged heart may disrupt the heart’s electrical system, which can lead to cardiac arrest. This can sometimes result in sudden death.

• Heart failure: An enlarged heart has difficulty pumping blood through your body. This can lead to heart failure. Heart failure can cause fluid can build up in the body.2 If the fluid backs up into the lungs, you may have trouble breathing.

• Heart murmur: An enlarged heart can disrupt the heart's normal anatomy, making it difficult for valves to close properly. This can cause a backflow of blood that can be heard by a cardiologist when listening to the heart with a stethoscope. Although heart murmurs may be benign, they may also be an ominous sign of impending heart failure and should therefore be monitored closely.

What Is the Life Expectancy of Someone With an Enlarged Heart?

The life expectancy for someone with an enlarged heart varies according to what is causing the condition. For example, only around 34% of those with dilated cardiomyopathy will survive 15 years or more, while those with hypertrophic cardiomyopathy tend to have a normal life expectancy.34

How Is an Enlarged Heart Treated?

If an enlarged heart is due to pregnancy or strenuous exercise, it may return to its normal size. But most underlying causes will require treatment. 

Your healthcare provider will usually recommend lifestyle changes such as quitting smoking, reducing your intake of alcohol, and eating foods low in sodium. You may also be prescribed certain medications, such as:

• Antiarrhythmics to treat an abnormal heart rate

• Blood pressure medication such as angiotensin-converting enzyme (ACE) inhibitors or beta-blockers

• Diuretics to help control the fluid and sodium in your body

• Anticoagulants to help prevent blood clots

You may also require surgery such as coronary artery bypass surgery. Some people also need implanted medical devices such as a pacemaker or an implantable cardioverter defibrillator (ICD).

When to See a Healthcare Provider

Whether you or a loved one has an enlarged heart, learning about what symptoms to look out for will not only help you to know what to expect, but it may also be lifesaving. In medicine, the saying "time is tissue" means the sooner you get the help you need, the more likely you are to avoid life-threatening complications.

Seek Emergency Care

Seek immediate medical attention if you are experiencing any of the following symptoms:

• Severe chest pain

• Shortness of breath

• Dizzy spells or fainting

• Radiating pain or discomfort originating in the shoulder and going down the arms, back, neck, or stomach

The most devastating consequences of an enlarged heart are sudden cardiac arrest and heart attack.

If you have diabetes, high blood pressure, or a family history of heart disease, you may want to consider setting up routine appointments with a primary care physician and a cardiologist to monitor for any potential changes that may be taking place in your heart.

Summary

If you have any health condition that causes your heart to work harder than it should, you are at risk of developing cardiomegaly. An enlarged heart is usually the result of disease or health problems, but if the enlargement only lasts for a short while before returning to its normal size, there is likely a less ominous explanation—like pregnancy or a history of strenuous exercise.

Cardiomegaly may be a symptom of a potentially life-threatening disease, so it is important to contact a healthcare professional if you are experiencing any of the aforementioned symptoms, have a family history of heart disease, or have a history of heart or lung problems. Early diagnosis and management of the root causes of your enlarged heart can improve your prognosis.

4 Sources

Heart and Stroke Foundation of Canada. Enlarged heart. 

Harvard Health Publishing. Fluid retention: What it can mean for your heart.

Xu XR, Han MM, Yang YZ, et al. Fifteen-year mortality and prognostic factors in patients with dilated cardiomyopathy: persistent standardized application of drug therapy and strengthened management may bring about encouraging change in an aging society. J Geriatr Cardiol. 2022;19(5):335-342. doi:10.11909/j.issn.1671-5411.2022.05.003

Maron MS. Patient education: hypertrophic cardiomyopathy (beyond the basics). In: McKenna WJ, Dardas TF, eds. UpToDate; 2023.

By Shamard Charles, MD, MPH
Shamard Charles, MD, MPH is a public health physician and journalist. He has held positions with major news networks like NBC reporting on health policy, public health initiatives, diversity in medicine, and new developments in health care research and medical treatments.