What’s Causing This Pain Under My Left Breast?

Medically reviewed by Daniel Murrell, MD on October 5, 2017Written by Donna Christiano on October 5, 2017


The left side of the body houses a number of vital organs. Under and around the left breastbone are the heart, spleen, stomach, pancreas, and large intestine. And that’s in addition to the left lung, left breast, and left kidney, which actually sits higher in the body than the right one. When you experience pain under the left breast, it can have a variety of causes — some simple, some serious.

Causes: Heart and chest

1. Heart attack

Because the heart is located left and center in the chest — and because heart disease is the leading cause of death in America — a heart attack is often the first thing people think of when they experience pain near their left breastbone.


Squeezing, tightness, or pressure in the chest are common symptoms — but they don’t always occur. According to the National Heart, Lung, and Blood Institute, one-third of those experiencing heart attacks won’t have any pain. When there is pain, it can last for a few minutes or come and go. Learn more about the warning signs of a heart attack.

Other symptoms include:

  • shortness of breath
  • nausea and vomiting (usually more common in women)
  • fatigue
  • discomfort in the arm, shoulder, and jaw


Your doctor may recommend surgery. Angioplasty involves using a balloon to unclog a blocked coronary artery. A stent will likely be placed to keep the artery open. Coronary bypass surgery takes a healthy blood vessel from another part of the body and grafts it to “bypass” a blocked artery. Here’s what you need to know about coronary bypass surgery and alternative treatments.


A healthy diet (one that is rich in fruits, vegetables, lean meats, whole grains, omega-3 fatty acids, and low-fat dairy) can help prevent high cholesterol and high blood pressure and promote a healthy weight. Consider adding foods that can help lower your blood pressure.

Moderate-to-vigorous physical activity can have similar effects. The American Heart Association recommends aiming for 30 minutes per day, 5 days a week. This can help prevent heart disease.

ACE inhibitors can decrease blood pressure and reduce the heart’s workload while statins can lower cholesterol and plaque buildup on artery walls. These buildups can block arteries and cause a heart attack.

2. Pericarditis

This is an inflammation of the pericardium, the thin, two-layered membrane that surrounds the outside of the heart. Pain occurs when the irritated membrane rubs against the heart. It can be caused by a number of factors — some preventable, some not. They can include an autoimmune disease (a disease in which the body fights healthy cells) such as lupus or rheumatoid arthritis, an infection, heart attack, and chest injury.


Sharp, stabbing pain in the chest is a common symptom. According to the Cleveland Clinic, the pain intensifies when lying down, coughing, or swallowing. Pain can radiate to the back, neck, and shoulder.

Tiredness and anxiety are also common symptoms of pericarditis.


Your doctor may advise anti-inflammatories, antibiotics (if the cause is bacterial), steroids, or pain relievers. In some cases, your doctor will recommend draining any fluid in the pericardium.


When you’re experiencing symptoms, seek treatment promptly, rest, and follow your treatment plan diligently. Protect yourself from heart disease by following the tips above. Always wear a seatbelt and proper protective sporting equipment when engaging in contact sports.

3. Precordial catch syndrome

Most prevalent in older children and young adults, this condition occurs when the nerves of the chest wall become pinched or irritated. According to the Children’s Hospital of Wisconsin, this can happen due to an injury to the chest, a growth spurt, or even bad posture. While precordial catch syndrome can mimic some of the symptoms of a heart attack, it’s a harmless condition that resolves on its own. Most people, in fact, will outgrow it by their mid-20s.


  • sharp, stabbing pain, often on the left side of the chest
  • sudden onset
  • short-lived (three seconds to three minutes)
  • pain that intensifies with deep breathing


For pain, your doctor will likely recommend over-the-counter (OTC) pain relievers like acetaminophen (Tylenol).


Relaxation techniques (such as imagining a calm, serene scene) to reduce anxiety may be helpful. Improving posture (sit with head up, shoulders back) will keep the chest cavity open and reduce pinching. Deep breathing — while it can increase the pain — can also help to resolve an attack.

4. Pleurisy

This condition results when the membrane that surrounds the lungs and lines the inside of the chest cavity becomes irritated and inflamed. Common causes include a viral infection, such as the flu, or a bacterial infection, such as bacterial pneumonia. When the left lung is affected, left-side pain will result.


  • chest pain, especially when breathing
  • shallow breaths (to avoid painful deep breathing)


Your doctor will focus on treating the underlying cause of the condition. After that, the Mayo Clinic recommends OTC pain relievers like Tylenol or ibuprofen (Advil, Motrin IB).


Rest in a comfortable position and apply an ice pack to the chest.

5. Costochondritis

An inflammation of the cartilage that attaches your ribs to the breastbone, costochondritis affects more women than men and generally occurs after age 40. The Mayo Clinic reports that it’s generally felt on the left side of the breast. Causes include an injury to the rib cage, heavy lifting, an infection, and arthritis. Experts note, however, that it often has no identifiable cause.


  • sharp, aching pain or pressure
  • pain that worsens with coughing or sneezing


Your doctor may recommend OTC or prescription-strength pain relievers and anti-inflammatories or steroids.


Heat and cold therapy and bed rest will help relieve the pain. Avoid running, weight lifting, and manual labor, as they can worsen the problem.

6. Chest injuries

Any blow to the chest — from a fall, car accident, or playing sports — can break or crack a rib or bruise the chest. When it happens on the left side of the body, there can be serious complications. For example, the jagged edges of a broken rib may puncture the liver or spleen.


  • tenderness where the injury occurred
  • painful deep breathing
  • pain when you twist


Your doctor will recommend or prescribe pain-relieving medication.


Deep-breathing exercises will help prevent shallow breathing and the risk of developing pneumonia. Wearing a seatbelt and protective sporting equipment will help protect the chest.

Causes: Digestive issues

1. Gastritis

The stomach sits in the upper region of the left side of the body. When its lining becomes inflamed and irritated — thanks to things like infections, the use of certain medications, spicy foods, and chronic alcohol use — pain can develop.


  • indigestion
  • nausea and vomiting
  • abdominal fullness
  • pain in the upper-left portion of the body


Your doctor may recommend OTC or prescription antacids as well as acid-reducing medications. If these don’t resolve the issue and bacteria are found to be the cause of your gastritis (many cases are tied to the bacterium H. pylori), you’ll be prescribed antibiotics.


Avoid alcohol and spicy or hard-to-digest fatty foods. Eat small, frequent meals. You may want to try adding certain herbs to your diet. Ask your doctor if you can safely take myrrh, licorice, or clove.

2. Pancreatitis

The pancreas sits tucked behind the stomach. Pancreatitis is an inflammation of the pancreas that occurs when digestive enzymes are inappropriately activated while still in the pancreas, causing irritation.


  • upper abdominal pain, especially when it radiates around the back
  • nausea and vomiting
  • fever
  • oily stools


Pain medication and anti-nausea medication can be beneficial. Surgery — for example, to remove gallstones if they’re the cause of the pancreatitis or to unblock any bile ducts in the pancreas — may also be suggested by your doctor.


Because smoking, excessive alcohol intake, and a fatty diet can all contribute to pancreatitis, changing those habits can help.

3. Heartburn

When digestive acids start to erode the lining in your esophagus (windpipe), it can create a burning sensation in your throat and upper chest. Some people experience the pain behind the left breastbone and mistake it for a heart attack.


  • sharp, burning pain
  • tightness in chest
  • pain that usually occurs after eating or while lying down
  • sour taste in mouth
  • feeling a small amount of stomach contents (regurgitation) rise up through the throat


Your doctor may recommend antacids, either prescription or OTC. Your doctor may also advise taking acid-reducing or acid-blocking medications.


Heartburn can be triggered by fatty or spicy foods, caffeine, alcohol, garlic, and carbonated drinks, so you may need to change your diet. Elevating the head of the bed (about 8–11 inches) can help reduce the esophagus’ exposure to stomach acid while sleeping. Check out these other post-meal tips to ease heartburn.

Causes: Other

1. Injury to the spleen

The spleen is an organ that sits to the left of the stomach and works primarily to filter blood. The Merck Manual reports that injuries to the spleen often result from car accidents, athletic injuries, beatings, and falls.

In addition, an enlarged spleen, which can result from certain viruses like mononucleosis (mono), can make the spleen more susceptible to injury. When the spleen is injured or even ruptures, it can leak blood into the abdominal cavity, irritating it. Since both the spleen and stomach sit on the left side of the body, upper-left pain isn’t uncommon.


  • tenderness in the upper-left portion of the body
  • dizziness and a drop in blood pressure if internal bleeding occurs
  • tight abdominal muscles


Surgery to repair or remove the damaged spleen is sometimes recommended. However, because the spleen helps the body fight infection, some doctors advocate against removing the spleen and instead encourage letting it heal on its own. Blood transfusions may also be necessary.


Wearing a seatbelt and protective equipment when playing contact sports is the best way to protect the spleen.

2. Hiatal hernia

A hiatal hernia is a condition that occurs when the upper part of the stomach pushes through the diaphragm (a muscle that separates the abdomen and the chest) into the chest cavity. When that happens, digestive acid can reflux into the esophagus. Because the stomach is located in the upper-left portion of the body, it’s not uncommon for pain to be felt there.


  • heartburn
  • pain that mimics a heart attack
  • belching
  • trouble swallowing
  • inability to pass gas or stools

Oftentimes there are no symptoms, however.


Medications to neutralize, reduce, or even prevent stomach acid or surgery to reposition the stomach into the abdominal cavity may be advised.


Obesity and smoking up the risk of having a hiatal hernia. You’ll be advised to quit smoking and lose weight if necessary. Not straining with a bowel movement and limiting the amount of acid-producing foods (spicy foods, tomatoes, chocolate, alcohol, and caffeine) can also help reduce your risk.

When to see a doctor

Any sudden, abnormal, or debilitating pain — left side or otherwise — needs immediate medical attention. While not an exhaustive list, seek emergency care if you have:

  • tightness or pressure in the chest, especially if you’ve been diagnosed with heart problems or the pain is accompanied by sweating, nausea, and shortness of breath
  • trouble breathing
  • an injury to the chest
  • changes in your stools — either you can’t pass them or they look bloody, oily, or resemble tar
  • pain that doesn’t improve with rest or starts to radiate to other parts of the body


Given the vital organs located there, pain under the left breast isn’t uncommon. In most cases, it’s not a heart attack. But because the pain can be intense and the symptoms worrisome, it’s worth getting them evaluated. In many cases, the conditions can improve with medication and lifestyle adjustments.

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