Sternum pain

Sternum pain refers to discomfort or tenderness felt in the central chest region overlying the breastbone. It may arise from a wide variety of causes ranging from benign musculoskeletal strain to serious underlying cardiac, pulmonary, or gastrointestinal conditions. Understanding its anatomical basis, associated structures, and possible origins is essential for accurate diagnosis and appropriate management.

Anatomy of the Sternum

Location and Structure

The sternum, or breastbone, is a flat, elongated bone located in the anterior midline of the thoracic cage. It serves as a central point of attachment for the ribs and clavicles, providing structural support and protection to vital organs such as the heart, lungs, and major blood vessels. The sternum forms part of the thoracic skeleton that stabilizes the rib cage during respiration and movement of the upper body.

Parts of the Sternum

The sternum is divided into three main parts, each with distinct anatomical features and clinical significance:

• Manubrium: The upper portion of the sternum that articulates with the clavicles and the first pair of ribs. It forms the superior border of the thoracic inlet and can be palpated at the level of the jugular notch.
• Body (Gladiolus): The elongated central portion that articulates with the costal cartilages of the second to seventh ribs. It provides broad surfaces for muscular and ligamentous attachment.
• Xiphoid Process: The smallest and most inferior segment of the sternum, often cartilaginous in youth and ossified with age. It serves as an attachment site for the diaphragm, rectus abdominis, and transversus thoracis muscles.

Articulations and Surrounding Structures

The sternum articulates with the clavicles at the sternoclavicular joints and with the costal cartilages at the sternocostal joints. The manubriosternal joint forms the sternal angle, a palpable landmark used to locate the second rib and intercostal spaces during clinical examination. Surrounding structures include the mediastinum posteriorly, which contains the heart and great vessels, and the pectoralis major muscles anteriorly, which provide soft tissue coverage.

Vascular and Nerve Supply

The arterial supply of the sternum is derived primarily from branches of the internal thoracic arteries, with venous drainage occurring through the internal thoracic and anterior intercostal veins. Innervation is provided by the anterior branches of the intercostal nerves, which transmit sensory information from the periosteum and overlying skin. This close vascular and neural relationship explains why pain originating in or near the sternum can be sharp, localized, or referred to adjacent areas such as the chest wall and upper abdomen.

Overview of Sternum Pain

Definition and Description

Sternum pain, also known as anterior chest wall pain, refers to discomfort localized to the central chest region corresponding to the sternum. The pain may be dull, aching, or sharp and can vary in intensity from mild tenderness to severe pressure-like discomfort. It may be constant or intermittent and may radiate to the ribs, shoulders, or upper back depending on the underlying cause.

Mechanisms of Pain Generation

Pain in the sternal region arises from irritation or injury to the bone itself, surrounding joints, muscles, ligaments, or adjacent viscera. In musculoskeletal causes such as costochondritis or trauma, inflammation of the costal cartilage or periosteum triggers localized pain and tenderness. In cardiac or pulmonary causes, ischemia or inflammation produces referred pain through shared nerve pathways. Gastrointestinal reflux or esophageal disorders can also cause retrosternal pain through visceral irritation and referred neural transmission.

Differentiating Musculoskeletal vs Non-Musculoskeletal Pain

Differentiating between benign and serious causes of sternum pain is clinically vital. Musculoskeletal pain is typically localized, reproducible on palpation, and aggravated by movement or deep breathing. In contrast, cardiac pain often presents as diffuse, pressure-like discomfort not influenced by motion and may be accompanied by systemic symptoms such as sweating or shortness of breath. The table below summarizes key differences between common causes of sternum pain.

Feature	Musculoskeletal Pain (e.g., Costochondritis)	Cardiac Pain (e.g., Angina, MI)	Gastrointestinal Pain (e.g., GERD)
Onset	Gradual or after strain/trauma	Sudden, may occur with exertion	Gradual, often post-meal or lying down
Character	Sharp, localized, reproducible on palpation	Pressure-like, squeezing, non-localized	Burning or aching behind sternum
Aggravating Factors	Movement, deep breathing, touch	Physical exertion, emotional stress	Spicy food, recumbency, alcohol
Relieving Factors	Rest, analgesics	Rest, nitrates	Antacids, upright posture
Associated Symptoms	Local tenderness only	Dyspnea, diaphoresis, nausea	Heartburn, regurgitation

Causes of Sternum Pain

Musculoskeletal Causes

Musculoskeletal disorders are among the most common and benign causes of sternum pain. They usually result from inflammation, trauma, or mechanical strain affecting the joints, muscles, or cartilage connected to the sternum.

• Costochondritis: Inflammation of the costal cartilage where the ribs meet the sternum causes localized tenderness and pain that worsens with movement, deep breathing, or palpation.
• Tietze Syndrome: A rare condition similar to costochondritis but characterized by visible swelling of the affected costal cartilage, usually involving the second or third rib.
• Sternal Fracture or Contusion: Caused by blunt trauma or high-impact injury to the chest, leading to sharp pain, bruising, and sometimes difficulty breathing.
• Arthritis of Sternoclavicular or Sternocostal Joints: Degenerative or inflammatory joint disease can produce chronic anterior chest wall pain and stiffness.
• Muscle Strain or Injury: Overuse or sudden contraction of the pectoralis major or intercostal muscles can lead to pain over the sternum, particularly following heavy lifting or strenuous exercise.

Cardiac Causes

Cardiac conditions are among the most serious causes of sternum pain and must be ruled out promptly. The pain typically results from myocardial ischemia, inflammation, or pericardial involvement.

• Angina Pectoris: Caused by transient myocardial ischemia due to reduced coronary blood flow. The pain is typically described as pressure-like, radiating to the arm, neck, or jaw, and often triggered by exertion or stress.
• Myocardial Infarction: Characterized by prolonged, severe substernal pain not relieved by rest or nitrates. It is often accompanied by sweating, nausea, shortness of breath, and anxiety.
• Pericarditis: Inflammation of the pericardial sac produces sharp, pleuritic chest pain that worsens with inspiration and lying flat but improves when sitting forward.

Pulmonary Causes

Respiratory conditions can cause referred pain to the sternum due to pleural inflammation, pulmonary vascular obstruction, or direct chest wall involvement.

• Pleuritis: Inflammation of the pleura leads to sharp, localized chest pain aggravated by breathing or coughing.
• Pulmonary Embolism: A blood clot in the pulmonary arteries can cause sudden substernal pain, shortness of breath, tachycardia, and, in severe cases, collapse.
• Pneumothorax: Air in the pleural cavity results in sudden onset of sharp chest pain and respiratory distress, often accompanied by asymmetrical chest expansion.

Gastrointestinal Causes

Pain referred from the upper gastrointestinal tract may mimic sternal or cardiac pain, especially when associated with reflux or esophageal irritation.

• Gastroesophageal Reflux Disease (GERD): Acid reflux causes burning retrosternal pain that worsens after meals or when lying down.
• Esophagitis or Esophageal Spasm: Inflammation or abnormal muscular contractions of the esophagus may produce pain radiating to the sternum and throat.
• Hiatal Hernia: Herniation of the stomach through the diaphragm can cause discomfort or pressure behind the sternum, often exacerbated by bending or eating.

Other or Rare Causes

• Anxiety or Panic Disorders: Psychological stress can cause chest tightness and discomfort resembling cardiac pain, often accompanied by palpitations and shortness of breath.
• Sternal Tumors or Metastasis: Malignant lesions originating from or spreading to the sternum may present as persistent, localized pain or swelling.
• Infections (Osteomyelitis, Mediastinitis): Bacterial infection of the sternum or mediastinum following trauma or surgery can cause severe, deep-seated pain and fever.

Pathophysiology

Inflammatory Mechanisms

Inflammation plays a major role in many cases of sternal pain, particularly in costochondritis, arthritis, and infectious conditions. Cytokine-mediated inflammation of the costal cartilage or periosteum results in localized tenderness, warmth, and swelling. In systemic inflammatory diseases such as rheumatoid arthritis, autoimmune activity may also affect the sternocostal joints, contributing to chronic pain and stiffness.

Ischemic Mechanisms

Cardiac-related sternum pain arises primarily from ischemia of the myocardium. When coronary blood flow is insufficient, anaerobic metabolism leads to the accumulation of metabolites such as lactic acid and adenosine, which stimulate cardiac nociceptors. The resulting pain is typically deep, diffuse, and poorly localized, often radiating to adjacent areas due to shared visceral afferent pathways.

Referred Pain Mechanisms

Referred pain occurs when sensory nerve fibers from different regions converge on the same spinal segments. For example, cardiac pain is referred to the sternum and left arm through sympathetic afferents entering the spinal cord at T1–T5 levels. Similarly, esophageal pain may be perceived retrosternally due to shared vagal innervation. This overlapping neural input complicates differentiation between visceral and somatic sources of sternal discomfort.

Clinical Features

Nature and Location of Pain

The pain associated with sternum discomfort can vary widely depending on the underlying cause. It may be sharp, dull, aching, or pressure-like and typically occurs in the midline of the chest over the sternum. In musculoskeletal conditions, pain is often localized and reproducible with palpation or movement, whereas cardiac or gastrointestinal causes usually produce diffuse, deep pain that may radiate to other regions such as the arm, neck, or upper abdomen.

Associated Symptoms

Identifying accompanying symptoms helps differentiate among potential causes of sternal pain. These symptoms often provide valuable diagnostic clues:

• Shortness of Breath: Common in cardiac or pulmonary disorders such as angina, myocardial infarction, or pulmonary embolism.
• Palpitations: May indicate arrhythmia or heightened sympathetic activity in anxiety-related pain.
• Cough or Fever: Typically associated with pulmonary infections or inflammatory conditions like pleuritis or mediastinitis.
• Heartburn or Dysphagia: Suggestive of gastroesophageal reflux disease (GERD) or esophageal irritation.
• Localized Swelling or Tenderness: Seen in costochondritis, Tietze syndrome, or traumatic injury.

Aggravating and Relieving Factors

The pattern of pain aggravation and relief provides additional diagnostic value. Pain that worsens with movement, deep breathing, or palpation suggests a musculoskeletal origin, whereas pain triggered by exertion, stress, or cold exposure may indicate cardiac ischemia. Gastrointestinal pain is often aggravated after eating, especially with acidic or spicy food, and may improve with antacids or upright posture. Anxiety-induced chest pain may occur spontaneously and subside with relaxation or breathing exercises.

Distinguishing Characteristics of Common Conditions

The table below outlines key distinguishing features of frequently encountered causes of sternum pain, aiding in clinical differentiation.

Condition	Pain Characteristics	Associated Findings	Relieving Factors
Costochondritis	Localized, sharp, reproducible on palpation	Chest wall tenderness, normal ECG	Rest, anti-inflammatory medications
Angina Pectoris	Pressure-like, diffuse, radiates to arm or jaw	Triggered by exertion, relieved by rest	Rest, nitrates
GERD	Burning retrosternal discomfort	Occurs after meals or lying down	Antacids, upright posture
Pleuritis	Sharp, stabbing pain with inspiration	Associated cough or fever	Anti-inflammatory therapy
Anxiety or Panic Attack	Tightness or heaviness, episodic	Palpitations, sweating, sense of fear	Relaxation techniques, anxiolytics

Diagnostic Evaluation

History and Physical Examination

A detailed history is essential to determine the onset, duration, nature, and associated symptoms of sternum pain. The clinician should inquire about recent physical activity, trauma, emotional stress, or underlying diseases. Physical examination includes inspection and palpation of the chest wall for tenderness, swelling, or deformity, as well as auscultation for cardiac or respiratory abnormalities.

Laboratory Investigations

Laboratory tests help identify systemic inflammation, infection, or cardiac injury. The following investigations are commonly performed:

• Cardiac Enzymes (Troponin, CK-MB): Elevated levels indicate myocardial injury or infarction.
• Inflammatory Markers (CRP, ESR): Raised values suggest inflammatory or infectious etiologies such as costochondritis or mediastinitis.
• Complete Blood Count (CBC): May reveal leukocytosis in infection or anemia in chronic disease.

Imaging Studies

• Chest X-ray: Useful for identifying fractures, pneumonia, or mediastinal widening suggestive of serious pathology.
• CT or MRI of the Chest: Provides detailed visualization of the sternum, costal cartilages, and mediastinum, aiding in the diagnosis of fractures, tumors, or infections.
• Bone Scan: Helps detect occult sternal fractures or metastatic lesions when plain radiographs are inconclusive.

Cardiac and Pulmonary Tests

• Electrocardiogram (ECG): Identifies ischemic changes, arrhythmias, or pericardial involvement.
• Echocardiogram: Assesses cardiac function, wall motion abnormalities, and pericardial effusion.
• Pulmonary Function Tests: Evaluate lung capacity and detect restrictive or obstructive pulmonary disorders contributing to chest pain.

Gastrointestinal Evaluation

• Upper GI Endoscopy: Useful for visualizing esophagitis, ulcers, or hiatal hernia in patients with reflux-related sternum pain.
• Esophageal pH Monitoring: Measures acid exposure in the esophagus, confirming GERD as the source of retrosternal discomfort.

Complications

Progression of Underlying Disease

Untreated sternum pain may signify progression of the underlying disease process. In musculoskeletal disorders, chronic inflammation can lead to calcification of the costal cartilage or joint stiffness. In cardiac conditions, recurrent ischemia may progress to myocardial infarction or heart failure. Similarly, untreated pulmonary or gastrointestinal causes may result in respiratory compromise or esophageal ulceration, respectively.

Chronic Pain Syndromes

Persistent sternum pain can evolve into a chronic pain syndrome due to continuous nociceptor stimulation and central sensitization. Patients may develop long-term chest discomfort, hypersensitivity, and muscle tension even after the initial cause resolves. Chronic pain can lead to psychological distress, sleep disturbances, and reduced quality of life if not addressed through multidisciplinary management.

Functional Limitations and Anxiety

Recurrent or severe chest pain often leads to anxiety and activity avoidance, particularly when cardiac causes are suspected. Fear of exertion may reduce physical fitness, leading to deconditioning and worsening fatigue. In some individuals, this cycle of fear and avoidance can perpetuate symptoms even in the absence of ongoing pathology. Early reassurance and patient education are essential to prevent such outcomes.

Treatment and Management

General Principles

Treatment of sternum pain focuses on identifying and addressing the underlying cause while providing symptomatic relief. A thorough diagnostic workup ensures appropriate management tailored to the specific etiology. In all cases, reassurance, rest, and gradual return to normal activities are important aspects of care. Analgesics, physical therapy, and lifestyle modification form the cornerstone of conservative management.

Management of Musculoskeletal Causes

• Analgesics and Anti-inflammatory Drugs: Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or naproxen are effective for relieving pain and reducing inflammation in costochondritis or minor trauma.
• Physical Therapy and Postural Correction: Gentle stretching, strengthening of chest and shoulder muscles, and correction of postural imbalances help reduce strain on the sternocostal joints.
• Local Injections: In cases of severe or persistent pain, corticosteroid or lidocaine injections into the affected costochondral joint can provide targeted relief.
• Heat or Cold Therapy: Application of heat promotes muscle relaxation, while cold therapy reduces inflammation and swelling following acute injury.

Management of Cardiac Causes

• Antianginal Therapy: Nitrates, beta-blockers, and calcium channel blockers improve coronary blood flow and relieve ischemic chest pain.
• Antiplatelet and Anticoagulant Agents: Aspirin, clopidogrel, and heparin are used to prevent thrombus formation in acute coronary syndromes.
• Reperfusion Therapy: In myocardial infarction, timely interventions such as percutaneous coronary intervention (PCI) or thrombolytic therapy are life-saving measures.
• Cardiac Rehabilitation: Post-treatment rehabilitation programs emphasize exercise, diet modification, and risk factor management to prevent recurrence.

Management of Pulmonary and GI Causes

• Antibiotics or Anti-inflammatory Drugs: Used in infections such as pneumonia, pleuritis, or mediastinitis to control inflammation and prevent complications.
• Proton Pump Inhibitors (PPIs): Medications like omeprazole or pantoprazole reduce gastric acid secretion, providing relief in GERD and esophagitis-related sternal pain.
• Lifestyle and Dietary Modifications: Avoiding large meals, maintaining an upright posture after eating, reducing caffeine and alcohol intake, and achieving healthy weight are effective in managing reflux-related discomfort.

Psychological and Supportive Care

Patients with anxiety-induced sternum pain benefit from counseling, relaxation techniques, and, when necessary, pharmacological therapy using anxiolytics or antidepressants. Cognitive-behavioral therapy (CBT) helps address maladaptive thought patterns and reduces symptom-related anxiety. Educating patients about the benign nature of non-cardiac chest pain promotes reassurance and adherence to treatment.

Prognosis

Outcomes Based on Underlying Cause

The prognosis of sternum pain largely depends on the underlying cause and the timeliness of diagnosis and treatment. Musculoskeletal conditions such as costochondritis or minor trauma generally have an excellent prognosis and resolve within weeks with conservative management. Cardiac-related sternum pain, particularly from myocardial infarction or unstable angina, carries a guarded prognosis unless promptly treated. Pulmonary embolism or mediastinal infections represent medical emergencies with potentially life-threatening outcomes if not managed urgently.

Factors Affecting Recovery

Recovery outcomes are influenced by factors such as patient age, comorbidities, severity of the underlying condition, and adherence to treatment. Early intervention, lifestyle modification, and appropriate rehabilitation significantly improve long-term outcomes. In chronic cases, persistent inflammation or poor posture may delay healing, requiring ongoing physiotherapy and postural correction. Psychological factors, including anxiety and depression, can also slow recovery by heightening pain perception and reducing treatment adherence.

Chronic and Recurrent Cases

Some individuals experience recurrent or chronic sternum pain, especially those with postural dysfunction, degenerative joint disease, or anxiety-related disorders. Chronic pain may necessitate a multidisciplinary approach involving pain specialists, physiotherapists, and mental health professionals. Long-term management focuses on maintaining mobility, reducing inflammation, and addressing psychosocial components of pain to improve quality of life and prevent recurrence.

Prevention

Lifestyle Measures

Adopting a healthy lifestyle can significantly reduce the risk of developing sternum pain. Regular exercise strengthens the chest and shoulder muscles, promoting better posture and reducing mechanical strain on the sternocostal joints. Maintaining a balanced diet, controlling weight, and avoiding smoking or excessive alcohol consumption contribute to overall cardiovascular and musculoskeletal health.

Posture and Ergonomics

Good posture plays a crucial role in preventing musculoskeletal sternum pain. Ergonomic adjustments such as maintaining an upright seated position, using supportive chairs, and avoiding prolonged slouching minimize pressure on the anterior chest wall. For individuals engaged in physical labor or sports, proper warm-up, stretching, and use of protective gear help prevent strain and trauma to the sternum and surrounding muscles.

Preventing Recurrence of Cardiac and GI Causes

For patients with a history of cardiac or gastrointestinal conditions, preventive measures are key to avoiding recurrence of sternum pain. Adhering to prescribed medications, monitoring blood pressure and cholesterol levels, and following a heart-healthy diet lower the risk of cardiac events. Similarly, for reflux-related pain, dietary modification, weight control, and avoidance of late-night meals or recumbency after eating can prevent symptom recurrence. Regular medical follow-up ensures timely detection and management of potential complications.

References

1. Standring S, editor. Gray’s Anatomy: The Anatomical Basis of Clinical Practice. 42nd ed. London: Elsevier; 2021. p. 1052–1055.
2. Moore KL, Dalley AF, Agur AMR. Clinically Oriented Anatomy. 8th ed. Philadelphia: Wolters Kluwer; 2018. p. 74–77.
3. Tintinalli JE, Ma OJ, Yealy DM, et al., editors. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 9th ed. New York: McGraw-Hill Education; 2020. p. 496–505.
4. O’Keefe JH, Hammill SC, Freed MS. Cardiology for the Primary Care Physician. 3rd ed. Totowa, NJ: Humana Press; 2004. p. 155–168.
5. Parsons JP, Mastronarde JG. Chest pain and musculoskeletal disorders. Clin Chest Med. 2010;31(3):583–592.
6. Bass C, Mayou R. Chest pain. BMJ. 2002;325(7364):588–591.
7. Ferguson MK, Little AG, Skinner DB. Clinical evaluation of chest wall pain. Chest. 1984;85(4):428–433.
8. DeFroda SF, Bokshan S, Sternlicht A, et al. Costochondritis: A review of pathophysiology, diagnosis, and treatment. Curr Rev Musculoskelet Med. 2019;12(4):519–525.
9. Yellon RF, Lichtenstein R, Avram R. Gastroesophageal reflux and noncardiac chest pain. Am J Gastroenterol. 1991;86(12):1785–1791.
10. Kapur S, Lerman BB. Evaluation and management of chest pain in the emergency department. Emerg Med Clin North Am. 2015;33(3):519–537.