Symptoms of an Enlarged Heart

An enlarged heart, also known as cardiomegaly, is a condition that occurs when the heart 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.

Cardiomegaly can be diagnosed via chest X-ray, but this is far from the best way to diagnose it. The chest X-ray may alert the physician to an enlarged heart, but the confirmatory, or true diagnosis, will come from additional, more specific testing such as an echocardiogram, cardiac MRI, or cardiac CT scan.

This article reviews the symptoms of an enlarged heart.

Common Symptoms of an Enlarged Heart

Verywell / Jessica Olah

Frequent Symptoms

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.

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

  • 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


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 a cardiac arrest. This can sometimes result in sudden death.
  • Heart failure: If the heart is so enlarged that it loses its ability to pump blood throughout the body, we call this heart failure. Heart failure can actually lead to pulmonary issues, edema, and difficulty breathing if fluid backs up into the lungs.
  • 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.

When to See a Healthcare Professional

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 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 the heart.


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.

An enlarged heart may also uncommonly be the result of normal cardiac adaptation, which has been experienced by conditioned athletes.

An enlarged heart may or may not be a cause for concern, but it is better to be safe than sorry. Early diagnosis and management of the root causes of your enlarged heart can improve your prognosis and pave the way to a heart-healthy life.

Frequently Asked Questions

  • What causes an enlarged heart?

    Any disease that makes the heart work harder can cause an enlarged heart. Diseases that are commonly associated with enlarged heart include anemia, arrhythmia, cardiomyopathy, congenital heart disease, heart valve disease, and thyroid disease.

  • Is having an enlarged heart serious?

    Yes, an enlarged heart (cardiomegaly) can pose a serious threat by increasing the risk of heart failure or stroke. This is because the heart has greater difficulty pumping blood. If the enlarged heart is due to pregnancy or strenuous exercise, it may return to its normal size. But most underlying causes will require treatment.

2 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Cleveland Clinic. Enlarged heart.

  2. Baker NC, Assal C, Shirani J. Clinical significance of cardiomegaly caused by cardiac adiposityThe American Journal of Cardiology. 2012;109(9):1374-1378. doi:10.1016/j.amjcard.2011.12.034

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.