The space directly behind your sternum (breastbone) contains some of the body’s most vital structures: the heart and its surrounding sac, the esophagus, the trachea, major blood vessels including the aorta, and portions of the lungs. Pain felt right under or behind the sternum can originate from any of these organs, from the chest wall itself, or even from anxiety-related mechanisms that have nothing to do with structural damage. That range of possibilities is exactly what makes substernal pain both common and tricky to sort out.
What Sits Behind the Sternum
Your sternum is a flat bone running down the center of your chest, roughly six inches long in most adults. It has three parts: the manubrium at the top (where your collarbones attach), the body in the middle, and the xiphoid process, a small cartilaginous tip at the very bottom. The sternum connects to the upper ribs through cartilage joints and forms the front wall of a central compartment called the mediastinum.
Inside that compartment, the organs are stacked in layers. Closest to the sternum sits the heart, enclosed in a thin double-walled sac called the pericardium. Behind the heart runs the esophagus, the muscular tube that carries food from your throat to your stomach. The trachea (windpipe) and its two main branches sit above and behind the heart. The aorta, the body’s largest artery, arches up from the heart and curves downward along the spine. Major veins, lymph nodes, nerves, and the thymus gland fill the remaining space. The sternum itself can have natural openings or foramina, small perforations that are usually harmless but can occasionally complicate procedures like bone marrow sampling.1PubMed Central. Prevalence and morphometry of sternal and xiphoid foramen: a meta-analysis on 16,666 subjects
At the very bottom of the sternum, the xiphoid process points downward toward the upper abdomen. This is why pain “right under the sternum” can feel like it sits in the stomach area. The xiphoid overlies the top of the liver on the right, the stomach and spleen on the left, and the diaphragm muscle that separates the chest from the abdomen. Any of these structures, from the heart all the way down to the stomach, can generate pain that you feel in roughly the same spot.
Esophageal Causes and Why They Mimic Heart Pain
If you have ever had heartburn or acid reflux, you already know that the esophagus can produce a burning or pressure sensation right behind the sternum. Gastroesophageal reflux disease (GERD) is the most familiar culprit, but the esophagus can cause substernal pain through several other mechanisms too: abnormal muscle contractions (spasm), heightened sensitivity of esophageal nerves, or inflammation of the lining.
These esophageal problems are among the most common non-cardiac explanations for chest pain. Up to about 30 percent of patients who undergo cardiac catheterization for chest pain turn out to have normal coronary arteries, and in a large share of those people, the pain actually originates from the esophagus.2PubMed Central. Diagnosis and management of esophageal chest pain The reason this is so confusing is that esophageal and cardiac pain can feel nearly identical: both produce retrosternal pressure or discomfort that can radiate to the arms or neck.
Research comparing emergency patients with confirmed heart disease to those with confirmed esophageal disease found that the classic features doctors associate with angina, like pain brought on by exertion, appeared equally often in both groups. Features that helped distinguish esophageal pain included pain that lingered as a background ache, pain that woke the person from sleep, and retrosternal discomfort that stayed in the center of the chest without spreading to the sides.3PubMed. Angina-like esophageal pain: differentiation from cardiac pain by history Even so, telling the two apart by symptoms alone is unreliable, which is why doctors often rule out heart problems first before investigating the esophagus.
Cardiac Causes of Substernal Pain
The heart sits directly behind the sternum, so it is naturally the organ clinicians worry about most when someone reports pain in that area. Several cardiac conditions produce substernal discomfort, each with its own character.
Angina and Heart Attack
Angina is chest pain caused by reduced blood flow to the heart muscle. It typically feels like pressure, squeezing, or heaviness behind the sternum, often triggered by physical exertion or emotional stress and relieved by rest. When a coronary artery becomes fully blocked, the result is a heart attack, and the pain tends to be more intense, longer-lasting, and accompanied by sweating, nausea, or shortness of breath. The reason this pain localizes behind the sternum rather than pinpointing the heart itself has to do with how pain signals from internal organs converge on the same spinal cord pathways as signals from the chest wall. Nerve cells in the upper thoracic spinal cord receive input from both the heart and the skin of the chest, which is why the brain interprets heart pain as coming from a broad area behind the breastbone rather than from a specific spot.4PubMed. Viscerosomatic convergence onto T2-T4 spinoreticular, spinoreticular-spinothalamic, and spinothalamic tract neurons in the cat
Pericarditis
Pericarditis is inflammation of the sac surrounding the heart. The pain is typically sharp rather than the dull pressure of angina, and it has a distinctive feature: it gets worse when you lie flat or take a deep breath, and improves when you lean forward. Case reports describe patients presenting with chest pain relieved by leaning forward, along with fever and signs of inflammation.5PubMed Central. Acute Pericarditis as an Initial Presentation of Neoplastic Disease: A Case Report That positional quality is one of the most reliable ways to suspect pericarditis before any tests are done. The pain can also radiate to the upper back or the trapezius ridge (the muscle between your neck and shoulder), which is unusual for other cardiac problems and can be a helpful clue.6Philippine Journal of Cardiology. A Rare Case of Acute Purulent Pericarditis Secondary to Invasive Streptococcal Infection (S. pyogenes) with Cardiac Tamponade in an Immunocompetent 37-Year-Old Female Most cases are caused by viral infections and resolve within a few weeks, though occasionally pericarditis signals something more serious.
Aortic Dissection
This is the most dangerous cause of substernal pain. In an aortic dissection, the inner layer of the aorta tears, allowing blood to force its way between the vessel’s layers. It classically presents as sudden, severe chest or back pain described as ripping or tearing in nature.7PubMed Central. Seeing the invisible: painless aortic dissection in the emergency setting The pain can start right behind the sternum and migrate to the back as the tear extends along the aorta. Case reports document patients experiencing sudden substernal chest pain during routine activities like using the bathroom, only to be diagnosed with a dissection that was initially mistaken for a musculoskeletal problem.8PubMed Central. Aortic Dissection Masquerading as Musculoskeletal Chest and Back Pain Aortic dissection is rare but can be fatal if not treated quickly, which is why any sudden tearing chest pain warrants immediate emergency care.
Musculoskeletal Pain at the Sternum
Not all substernal or sternal pain involves internal organs. The chest wall itself is a common source, and when it is the cause, the pain tends to be reproducible: pressing on the sore spot makes it worse.
Costochondritis is inflammation of the cartilage connecting your ribs to the sternum. It causes a localized, often sharp pain right along the sternal border that flares when you press on the affected joint, twist your torso, or take a deep breath. There is typically no swelling or redness (when visible swelling accompanies the tenderness, it is usually classified as Tietze syndrome instead).9bioRxiv. Costochondritis syndrome and thoracic-chest related pain: a scoping review Costochondritis is one of the most common reasons people show up to emergency departments with chest pain, and it resolves on its own or with anti-inflammatory medication in most cases.
Xiphodynia targets the very bottom of the sternum. The xiphoid process, that small piece of cartilage at the lower tip, can become irritated from trauma, repetitive strain, or sometimes for no identifiable reason. The pain radiates outward from that spot and can travel to the chest, abdomen, throat, and even the arms.10PubMed Central. Treatment and Management of Xiphoidalgia Because the xiphoid sits right where the chest meets the upper abdomen, xiphodynia is frequently mistaken for a stomach or heart problem. Some people notice a small lump at the bottom of the sternum that they worry about; in many cases, that lump is simply a prominent or slightly displaced xiphoid process. One case report described a patient who experienced pain at the lower sternum with an associated lump for over a year before the problem was identified as xiphodynia.11Semantic Scholar. Insidious onset of xiphodynia with an idiopathic origin — a rare case report
Pulmonary and Airway Causes
Your lungs flank the sternum on both sides, and the trachea sits behind its upper portion. Diseases involving these structures can produce pain felt in the substernal area.
Acute tracheitis and tracheobronchitis, usually caused by viral infections, produce a raw, burning sensation behind the sternum that gets worse with coughing. The accompanying cough is the giveaway: if your substernal discomfort started with a cold and flares every time you cough, inflamed airways are a likely explanation.
Pulmonary embolism, a blood clot that lodges in the lung’s arteries, can cause substernal or lateral chest pain that is often sharp and pleuritic (worse with breathing). The more prominent symptom, though, tends to be sudden shortness of breath. Research comparing people who had a pulmonary embolism to matched controls found that exertional breathlessness was roughly five times more common in the embolism group, and breathlessness that woke them from sleep was about seven times more common.12PubMed Central. Dyspnea after pulmonary embolism: a nation-wide population-based case–control study If sudden chest pain arrives alongside unexplained difficulty breathing, especially after prolonged immobility or a recent surgery, a pulmonary embolism needs to be considered urgently.
Pneumomediastinum and Other Rare Causes
Pneumomediastinum is a condition where air leaks into the mediastinum, the central compartment behind the sternum. The main symptom is usually severe central chest pain, and it can be accompanied by difficulty breathing, a crackling sensation under the skin of the neck and chest, and sometimes a change in voice quality.13PubMed Central. Pneumomediastinum It can happen after forceful vomiting, intense coughing, or physical trauma. In one case, a previously healthy young adult developed retrosternal chest pain, shortness of breath, and a distinctive crunching sound heard with a stethoscope after repeated episodes of forceful vomiting.14PubMed Central. Spontaneous Pneumomediastinum Following Severe Vomiting in a Previously Healthy Young Adult While pneumomediastinum sounds alarming, the spontaneous version (not caused by direct injury) is usually self-limiting and resolves with rest and observation.
Boerhaave syndrome, a spontaneous rupture of the esophagus, is a related but far more dangerous emergency. It typically follows forceful vomiting and causes severe pain in the lower chest and upper abdomen along with both gastrointestinal and respiratory symptoms.15PubMed Central. Spontaneous esophageal perforation (Boerhaave syndrome): Diagnosis with CT-esophagography One case involved a patient who developed acute retrosternal chest pain after vomiting and was found to have a distal esophageal perforation requiring drainage and antibiotics.16PubMed Central. Endoscopic Closure of a Spontaneous Esophageal Perforation Using an Over-the-Scope Clip (OTSC®): A Conservative Approach to Boerhaave Syndrome It is very rare, but since delayed diagnosis dramatically worsens outcomes, severe chest pain following vomiting should be evaluated quickly.
Anxiety and Panic-Related Chest Pain
Panic attacks are a frequently overlooked cause of substernal pain, and the experience can feel indistinguishable from a heart attack. The chest tightness or pain during a panic attack is real and physical, not imagined. It can arise through multiple pathways at once: hyperventilation tightens chest wall muscles, stress hormones increase heart rate and blood pressure, and the esophagus can go into spasm during periods of intense anxiety.17PubMed Central. Panic Disorder and Chest Pain: Mechanisms, Morbidity, and Management
The challenge is that people with panic disorder often develop a cycle: the chest pain triggers fear of a heart attack, which worsens the panic, which intensifies the pain. Many end up in emergency departments repeatedly, and after cardiac testing comes back normal, they may feel dismissed or not believe the diagnosis. One important thing to understand is that having panic disorder does not protect you from also developing heart disease. The two can coexist, and each episode still deserves a clinical judgment about whether something new is happening.
When the Pain Demands Immediate Attention
Given how many different organs share the space behind the sternum, some degree of diagnostic uncertainty is normal. But certain features push the probability of a serious cause high enough that you should not wait to find out. Emergency evaluation is warranted for:
- Sudden tearing pain: especially if it radiates to the back, suggesting aortic dissection.
- Crushing pressure with sweating or nausea: the classic heart attack presentation, though it can be subtler in women, older adults, and people with diabetes.
- New chest pain with shortness of breath: particularly if you have risk factors for blood clots, such as recent immobility, surgery, or use of estrogen-containing medication.
- Severe pain after vomiting: raises the possibility of esophageal perforation or pneumomediastinum.
- Pain with fainting or near-fainting: suggests a dangerous drop in blood pressure or cardiac output.
Emergency departments use combinations of history, physical exam, blood tests (especially troponin for heart damage), electrocardiograms, and imaging to sort through these possibilities. Research on emergency triage for chest pain shows that specific clinical variables can rapidly stratify patients into groups with very different likelihoods of a serious cardiac event, with some combinations indicating as high as a 91 percent probability and others as low as 4 percent.18PubMed Central. The Challenge of Triaging Chest Pain Patients: The Bernese University Hospital Experience The point is that doctors can narrow the field efficiently. You do not need to diagnose yourself; you just need to recognize when the situation calls for professional assessment rather than a wait-and-see approach.
Why the Same Spot Hurts for So Many Different Reasons
One reason substernal pain is such a diagnostic puzzle is the phenomenon of referred pain. Internal organs do not have the same precise nerve mapping that your skin does. When the heart, esophagus, or aorta sends pain signals, those signals travel along nerve fibers that converge onto the same spinal cord neurons that handle sensation from the chest wall. Your brain has no way to tell whether the incoming signal came from your heart muscle or your breastbone, so it interprets both as pain “behind the sternum.”4PubMed. Viscerosomatic convergence onto T2-T4 spinoreticular, spinoreticular-spinothalamic, and spinothalamic tract neurons in the cat
This convergence also explains why heart pain can radiate to the left arm or jaw, why esophageal spasm can mimic a heart attack so convincingly, and why stomach problems sometimes feel like chest problems. The xiphoid process sits right at the boundary between the chest and abdomen, so irritation there can feel like either an abdominal or a thoracic issue depending on the person. Understanding that pain location is a rough guide rather than a precise map helps explain why your doctor might investigate your heart, your stomach, and your chest wall for the same complaint before landing on an answer.
Sternal Anatomy Variations That Cause Worry
Some people discover a lump, dip, or unusual contour along their sternum and become anxious that something is wrong. In most cases, what they are feeling is a normal anatomical variant. The xiphoid process alone varies enormously between people: it can be flat, curved, forked, or angled, and it may project forward noticeably. Some people first notice it during weight loss, when reduced fat over the area makes the bony tip more prominent.
The sternum itself can have one or more small holes called sternal foramina, which are developmental variants present in a meaningful percentage of the population. A meta-analysis covering more than 16,000 subjects examined the prevalence and characteristics of these foramina and emphasized their importance in clinical settings: they pose no health risk on their own but can be mistaken for fractures or lesions on imaging, and they represent a potential hazard during procedures like sternal bone marrow biopsy if the practitioner is unaware of them.1PubMed Central. Prevalence and morphometry of sternal and xiphoid foramen: a meta-analysis on 16,666 subjects Similarly, incomplete fusion of the sternal segments during development can leave visible joints or slight ridges along the bone that feel abnormal to a person palpating their own chest but are perfectly benign.19PubMed Central. A Comprehensive Review of the Sternal Foramina and its Clinical Significance
If you have recently started paying attention to the area under your sternum because of pain or anxiety, you may notice features of your own anatomy that have been there your whole life. A hard bump at the very bottom of the breastbone is almost always the xiphoid process. A shallow dip or groove partway up the sternum is usually a developmental variant. Neither of these warrants concern in the absence of pain, swelling, or other symptoms, though mentioning them at a routine appointment can put your mind at ease.