While there are many important muscles that make up the human body, a muscle that works round the clock and basically powers the body, is the heart. And like other muscles, it is susceptible to illness. An enlarged heart is not a disease, rather it is a key and serious sign of some underlying condition, which may not be related to the heart itself. Enlargement can mean thicker outer walls and internal muscles, or an actual change in size and dimensions of the heart. Any change in the heart, can affect its functioning and indirectly, the working of other parts of the body. In this article, we take a detailed look at an enlarged heart condition, its causes and symptoms.

Causes of an Enlarged Heart

High Blood Pressure : The heart is one big muscle, that pumps blood with force. Like any muscle, overexertion makes it expand and contract, to perform its task. With high blood pressure, the heart has to work double to pump blood throughout the body. This increase in activity and force, makes the internal muscles of the heart thicker and larger. Hence your heart, on the whole, gets enlarged.

Dilation : The myocardium is affected and weakened. Hence blood is not pumped to the body efficiently and affects the functioning of other body parts. The weakened myocardium could be due to toxicity from alcohol abuse. Previous heart infections or diseases could leave the heart in a weak state, resulting in dilation. This cause of an enlarged heart is also called left ventricular hypertrophy, as the left side of the heart pumps blood to the body, and it usually becomes enlarged.

Heart Valve Disease : Just like pipes make up a drainage system, directing water flow, in the same way the heart has 4 valves to control the flow of blood in the right direction. If these valves are weakened or damaged by an infection, disorder or defect, then the passage of blood is hindered. So to make up for it, the heart has to pump more blood with more force, and enlarges itself to make the effort. Rheumatic fever and certain medications and treatments for diseases like cancer, can also cause this sort of problem.

Arrhythmia : if your heartbeat is abnormal, where it works slow or fast, as compared to what it should, then the heart rhythm is thrown off, and hence blood transfer is affected.

Pulmonary Hypertension : While the heart pumps blood throughout the body, its right side is dedicated to pumping blood to the lungs. If the artery involved here has high blood pressure, this area of the heart has to work more to pump blood and expands.

Congenital Heart Defects (CHD) : A genetic defect, present at birth, could result in a defected or irregular heart structure and muscles, so blood flow is unpredictable by default. With most defects, the heart has to put in more effort to do the same work, so congenital defects are a direct cause for an enlarged heart.

Anemia : A low red blood cell count, means less oxygen gets carried to cells and tissues. As your oxygen levels decrease, more blood must be pumped to make up for the deficit. Anemia is one of the rarer enlarged heart causes, as if it worsens and left untreated, the heart gets affected.

Hemochromatosis : Iron is a useful mineral needed for the proper functioning of the body. But if your body is unable to synthesize or handle it, it can build up in various organs and cause harm. One such vulnerable organ, is the heart. The heart muscle is weakened by the excess iron, and the left ventricle enlarges, as a consequence.

Amyloidosis : Similar in concept to hemochromatosis. Instead of iron, here excessive amyloid proteins can build up in tissues and organs. The excess proteins spread in the blood stream, and find their way to the heart. Once they accumulate on the heart, they hinder and disturb its normal functioning, causing it to become swollen.

Miscellaneous : Thyroid disorders like hypothyroidism, can affect the heart's size. Damage done by a heart attack and coronary heart disease are some other enlarged heart causes.


Sometimes an enlarged heart can have no signs or symptoms. But in most cases, here are some common symptoms:
  • Swelling or edema in parts of the body, mainly in the ankles
  • Shortness of breath
  • Coughing and wheezing often
  • Breathlessness at random times
  • Dizziness and fatigue
  • Chest pain
  • Abnormal heartbeat rate and pattern
It's clear from the above causes, that any condition that disturbs the heart's functioning, causes it to increase in size. Chest X-rays and cardiograms and echo are used to diagnose such irregularities in size. Treatment options often depend on the causing disorder. Pacemakers are used to regulate an irregular heartbeat. If a heart condition or disease is responsible, then specific medicines are used. Surgery procedures are for serious defects, like congenital or heart valve problems. Often an enlarged heart is a key sign of a serious condition, which shouldn't be ignored.