Unexpected pain can occur under the left breast for reasons that range from problems with digestion through to heart conditions. Some can be treated at home, but some can be medically more serious.
There are some organs in the upper left region of the body that could be the source of the pain. These include the stomach, heart, lungs, ribs, colon, pancreas, and spleen.
Doctors often group the most common causes of pain under the left breast into two main categories: digestive and heart-related.
This article looks at the different causes of pain under the left breast, their symptoms, and the treatment options available.
As the heart is situated slightly to the left of the midline in the upper body, pain under the left breast can sometimes indicate a heart problem.
Heart attack pain can cause a very strong, uncomfortable, crushing pressure or squeezing sensation, or it may feel like very bad heartburn. Some people may not experience any or only mild chest pain; this is more common in women, older people, and those with diabetes.
Other symptoms include:
- profuse sweating
- nausea or vomiting
- shortness of breath
- heavy, weak shoulders or arms
- severe pain traveling to the arm, jaw, neck, back, and elsewhere in the body
- a strong sense of anxiety or impending doom
If someone suspects a heart attack, they should call an ambulance immediately. While waiting, they should rest, and if they are not intolerant to aspirin, they should take an adult-dose tablet (300 milligrams) to help thin the blood.
Further treatment options will depend on when symptoms started and how soon the person having the attack can access the first stage of care.
If the cause of the attack is found to be a blocked coronary artery, the doctor may recommend a procedure called an angioplasty to open a blocked or severely narrowed coronary artery with a balloon and possibly place a stent.
When the heart muscle does not receive enough oxygen in the coronary artery blood supply, the resulting pain under the left breast or in the center of the chest is known as angina.
Associated symptoms include an uncomfortable feeling in the shoulders, arms, neck, jaw, or back. Angina pain can also feel like indigestion, and a person may also experience sweating, light-headedness, nausea, or shortness of breath.
Angina is a possible symptom of severe underlying heart disease, so anyone experiencing symptoms of angina should seek medical attention immediately. A doctor may prescribe medication, such as beta-blockers, ACE-inhibitors, statins, or aspirin.
The heart is surrounded and protected by a thin, layered, fluid-filled membrane called the pericardium. It can become inflamed due to infection or a disorder where the body's immune system attacks itself.
Symptoms of acute pericarditis include:
- sharp, stabbing pain under the left breast or in the chest
- pain in one or both shoulders
- pain worsening when taking a deep breath or lying down on the back
- feeling hot, sweaty, feverish, light-headed, and short of breath
Immediate treatment for pericarditis may include an OTC anti-inflammatory medication, such as ibuprofen and rest until feverish symptoms decrease. If a person experiences severe pain, a doctor may prescribe a steroid, such as prednisone.
If the condition is severe, the person may need to say in the hospital for monitoring.
Ibuprofen is available for purchase online.
While acute pericarditis typically cannot be prevented, getting treated quickly and following a prescribed treatment plan will reduce the chance of the acute pericarditis recurring or becoming a long-term condition.
When the stomach's lining becomes inflamed, this is known as gastritis. Not everyone will experience symptoms, but a sharp, stabbing or burning pain under the left breast is a potential clue that gastritis may be present.
The pain can also be accompanied by heartburn, feeling sick, vomiting, and bloating.
For mild symptoms, changing the diet and lifestyle can ease pain under the left breast. Over-the-counter (OTC) medications, such as antacids, can help reduce stomach acid.
Home remedy options include:
- reducing alcohol intake
- eating smaller portions more often, as opposed to one big meal
- cutting out dairy, spicy, fried, or acidic foods, and caffeinated drinks
- cutting down or giving up tobacco smoking
- reducing high intake of OTC non-steroidal anti-inflammatory drugs (NSAIDs)
- eating foods high in fiber and plant nutrients
If the pain is caused by or related to the presence of the bacterium called Helicobacter pylori, the doctor may prescribe a course of antibiotics and medicine that reduces the production of stomach acid.
- sudden, severe pain under the left breast and in the upper center part of the abdomen
- nausea and vomiting
- rapid pulse
Chronic pancreatitis, where the condition worsens over time, has symptoms including:
- frequent or prolonged episodes of pain under the left breast that can spread to the back
- nausea and vomiting
- oily, pale-looking stools
Treatment for chronic pancreatitis ranges from pain management, using increasing strengths of medication, to surgery if pain under the left breast is still severe.
For acute pancreatitis, immediate treatment includes:
- intravenous fluids to aid in hydration and ensure the body's other organs have good blood flow
- no eating for 24-48 hours, then following a high-calorie diet to support healing
- giving intravenous pain medication or antinausea medication
When stomach acid travels back up the food pipe, it causes a burning sensation in the mid-chest and throat, and sometimes pain under the left breast. Heartburn can be a symptom of indigestion and stomach acid issues.
- a tight, burning sensation in the upper chest or throat that sometimes travels under the left breast and the jaw
- a bitter taste in the mouth
- pain under the left breast or in the chest while lying down or just after eating
Self-help treatment options for mild heartburn include not eating big meals, not lying down to sleep right after eating, and raising one's pillow, so the head is higher than the waist when sleeping. This may help prevent stomach acid from traveling up the food pipe.
OTC medications such as antacids are a first medical option to try and are available for purchase online.
The lungs are surrounded by a layered membrane called the pleura. If the pleura surrounding the left lung become inflamed due to infection or another cause, the resulting pain will develop under the left breast.
The most common symptom of pleurisy is a sharp chest pain when taking a deep breath, but it can also be accompanied by:
- pain in the shoulder
- a dry cough
- shortness of breath
The pain can get worse when the person walks around, coughs, or sneezes.
Rest is highly recommended. Lying on the side of the pain can help relieve pain symptoms.
If a person experiences particularly severe chest pain, they should seek immediate treatment from a doctor, who may prescribe NSAIDs or other pain-relieving medication.
A doctor may also carry out further tests, such as blood tests, a chest X-ray, a chest CT scan. They may also take a small sample of pleural lung tissue for biopsy.
Pleurisy caused by a viral infection often gets better after a few days, but a bacterial infection will require antibiotic therapy.
The best way to prevent severe cases of pleurisy is early intervention.
The spleen can cause pain under the left breast if it is enlarged or if it bursts following an injury.
Symptoms of an enlarged spleen include:
- tenderness and pain under the left breast
- feeling uncomfortable when eating even just a small meal
- anemia and extreme tiredness
- bleeding easily
A burst spleen typically will cause:
- pain under the left breast or ribs, and tenderness when touched
- dizziness and fast heart rate
If a person suspects a burst spleen, they should go immediately to the emergency room. Bleeding can be life-threatening if left untreated.
Underlying conditions, such as chronic liver disease and subsequent cirrhosis, can affect and interact with the spleen.
A doctor will prescribe medication when medical therapy is possible to treat splenic or liver disease. Surgery is only required if underlying causes cannot be diagnosed clearly, or if complications arise from the enlarged or damaged organ.
People should aim to keep the spleen safe when playing sport by wearing protective sporting equipment. Always wearing the seatbelt when in the car is also advised.
As cirrhosis can be caused by excessive or long-term high alcohol intake, cutting down is recommended.
8. During pregnancy
Soreness and pain experienced under the left breast during pregnancy are often caused by pressure from the top of the uterus as it grows, or if the baby is kicking or punching the expectant mother. The pain can be worse when leaning forward.
Muscles and other tissues will stretch as the baby grows, and this can also cause pain under the breasts.
The expectant mother's body is changing during pregnancy, and the internal organs will be pushed and moved as the baby grows. The mother's body chemistry may also change, and other causes of pain under the left breast during pregnancy can include:
- heartburn with stomach acid reflux
- the rib cage changing position to allow space for the baby in the abdomen
Some conditions can be treated at home with rest and OTC medication, but people should seek medical attention straight away if:
- the chest is injured
- the pain under the left breast is unexpected
- symptoms of pain and tightness do not get better with rest
- shortness of breath, feeling sick, or profuse sweating accompanies the pain
Pain under the left breast is often frightening to experience. As there are several organs in this area of the body, the earlier the cause of the pain can be diagnosed, the more likely that treatment and recovery will be successful.
A heart attack is not the most common reason for pain under the left breast, but it is always better to have the symptoms checked out, especially if other symptoms of a heart attack are present.
Many causes of pain under the left breast can be prevented through making changes to several everyday lifestyle choices. Following a healthful diet, getting regular exercise, lowering or cutting out tobacco smoking, reducing alcohol intake, keeping weight down, and reducing stress can all help.