What Side Is Your Heart On? Where It Sits and Why It Matters

Put your hand over your heart. If you are like most people, it went to the left side of your chest, the way we do for the pledge or an anthem. That instinct is partly right and partly a myth, and the difference matters more than trivia: it changes how you read chest pain, and where you push if you ever need to do CPR.

This guide explains exactly where your heart sits, why you feel your heartbeat on the left, the rare people whose heart is on the right, and what left-sided or right-sided chest pain can and cannot tell you.

Quick Answer

Your heart is in the middle of your chest, behind your breastbone and between your lungs, tilted so that most of it sits slightly to the left. Its lower tip points down and to the left, which is why you feel your heartbeat most strongly just below the left nipple. It is not on the far left, and in a rare condition called dextrocardia it sits on the right. Because the heart is central, heart attack pain is usually felt in the middle of the chest, often spreading to the arm, jaw or back, and it is not always pain at all: in a US registry of over a million heart attack patients, 42 percent of women and 31 percent of men had no chest pain. For CPR, push in the center of the chest, on the lower half of the breastbone.

In this guide:

• Where Exactly Is Your Heart?
• Why You Feel Your Heartbeat on the Left
• Can Your Heart Be on the Right Side?
• Left or Right Chest Pain: What It Can Mean
• Where to Push for CPR
• The Verdict

Where Exactly Is Your Heart?

The heart is a muscular organ about the size of a fist, sitting in the center of the chest behind the sternum (breastbone). It lies in a space between the two lungs called the mediastinum, with the spine behind it and the diaphragm, the muscle that separates chest from abdomen, underneath.

It is not perfectly centered, though. The heart is turned and tilted, so roughly two-thirds of it lies to the left of the midline of your body and one-third to the right. Its broad top, called the base, where the large blood vessels attach, faces up and to the right, behind the upper breastbone. Its pointed bottom, the apex, angles down, forward and to the left. The left lung is slightly smaller than the right to make room for it.

Why You Feel Your Heartbeat on the Left

With each beat, the apex of the heart taps against the inside of the chest wall. Doctors call this the apex beat, and it is normally felt in the space between the fifth and sixth ribs, roughly in line with the middle of the left collarbone, which in many people is just below the left nipple. That is the spot where your heartbeat is easiest to feel, so it is where the idea of a “left-sided” heart comes from.

You may also feel your heartbeat more on the left when lying on your left side, because the heart moves slightly closer to the chest wall. Feeling your heartbeat strongly is usually normal, especially after exercise, caffeine or in a quiet room at night. A heartbeat that feels fast, irregular, fluttering or skipping, particularly with dizziness or breathlessness, is worth getting checked.

Can Your Heart Be on the Right Side?

Yes, in a few rare situations:

• Dextrocardia. A rare condition present from birth in which the heart sits in the right side of the chest with its tip pointing right. It is often found by chance, on a chest X-ray or heart tracing done for another reason.
• Situs inversus totalis. Dextrocardia together with a mirror-image arrangement of the other organs, so the liver is on the left and the stomach on the right. Many people with it are healthy, but it can come with other conditions: in a hospital study of 155 children with mirror-image organs, nearly half had a heart defect and about 1 in 8 had primary ciliary dyskinesia, a condition affecting the airways.
• Dextroposition. A normal heart pushed to the right by something else, such as a collapsed or removed right lung or a hernia through the diaphragm. Unlike dextrocardia, the heart still points left.

If you have dextrocardia, make sure it is on your medical record. Heart tracings (ECGs) look abnormal unless the leads are placed in mirror image, and pain from other organs, such as the appendix in situs inversus, can appear on the “wrong” side.

Left or Right Chest Pain: What It Can Mean

Because the heart is central, the side of chest pain is a poor guide to whether it is your heart. The 2021 US guideline on chest pain, from the American Heart Association, the American College of Cardiology and other societies, treats pain, pressure, tightness or discomfort anywhere in the chest, shoulders, arms, neck, back, upper abdomen or jaw as possible heart pain, and advises against dismissing any of it as “atypical”.

Heart attack pain is classically a pressure, squeezing or heaviness in the center of the chest that may spread to the left arm, both arms, the jaw or the back, often with breathlessness, sweating or nausea. But many heart attacks do not look like that. In the US National Registry of Myocardial Infarction, which covered 1,143,513 patients, 42 percent of women and 31 percent of men had no chest pain when they came to hospital. The gap between women and men was widest in younger patients, and younger women without chest pain were more likely to die in hospital than younger men without it.

Many other things cause chest pain on one side, and most are not dangerous:

• Muscles and ribs: a strained chest muscle or inflamed rib cartilage hurts when you press the spot, twist or take a deep breath.
• Heartburn: burning behind the breastbone, often after meals or lying down. It can feel very like heart pain, which is why heartburn and heart attacks are compared in can you die from acid reflux in your sleep.
• Lungs: pneumonia, a collapsed lung or a blood clot in the lung cause sharp pain on breathing, usually with breathlessness. These need urgent care.
• Right-sided upper belly pain spreading up under the ribs can come from the gallbladder, especially after fatty meals.
• Anxiety and panic attacks can cause chest tightness with a racing heart, but they are a diagnosis to make after heart causes are ruled out, not before.

Call 911 for chest pain or pressure lasting more than a few minutes or coming and going, pain spreading to the arm, neck, jaw or back, or chest discomfort with breathlessness, sweating, nausea, lightheadedness or fainting. Do the same for sudden breathlessness or unexplained exhaustion if you are at risk of heart disease, even without pain. Do not drive yourself to hospital.

Where to Push for CPR

Knowing where the heart really is matters most here. In adult CPR, the American Heart Association guidelines place the heel of one hand on the center of the chest, on the lower half of the breastbone, with the other hand on top, not over the left side. Push hard and fast: about 2 inches deep, at 100 to 120 compressions a minute, letting the chest come all the way back up between pushes. Call 911 first, or have someone else call, and use an automated external defibrillator (AED) as soon as one arrives; it talks you through each step.

Keeping your heart healthy in the first place comes down to the basics: regular activity, not smoking, and managing blood pressure, cholesterol and blood sugar. How exercise strengthens the heart is covered in how regular exercise improves your heart health, and why fitness predicts long-term health in what is physical fitness.

The Verdict

Your heart is in the center of your chest, behind the breastbone, tilted so most of it lies slightly left and its tip points down and left, which is where you feel your heartbeat. In rare cases it is on the right. Because it is central, heart pain is usually felt in the middle of the chest and can spread in many directions, and a large share of heart attacks, more often in women, come with no chest pain at all. So do not judge chest symptoms by which side they are on: call 911 for chest pressure, spreading pain or chest discomfort with breathlessness or sweating, and push on the center of the chest if you ever need to give CPR.