What causes back pain that worsens with deep breathing?

Back Pain Worsening with Deep Breathing

Back pain that worsens with deep breathing is a red flag symptom requiring immediate evaluation for pleuropulmonary pathology (pneumonia, pulmonary embolism, pleural effusion) rather than musculoskeletal causes, as this pattern indicates pleural or diaphragmatic irritation. 1, 2

Critical Distinction from Typical Low Back Pain

Standard mechanical low back pain does not worsen specifically with deep breathing. 3, 4 When respiratory movements exacerbate back pain, you must consider:

• Pleuropulmonary causes: Pneumonia, pulmonary embolism, pleural effusion, or pneumothorax can present with back pain as the primary or even sole complaint before respiratory symptoms become obvious 1, 2
• Diaphragmatic irritation: Conditions affecting the diaphragm or lower pleural surfaces refer pain to the back that intensifies with respiratory excursion 1
• COVID-19 pneumonia: Can present with thoracolumbar back pain as the leading symptom, even before dyspnea or cough become apparent 2

Algorithmic Diagnostic Approach

Step 1: Assess for Respiratory Pathology First

• Look for subtle respiratory signs: Even mild dyspnea that "doesn't affect everyday life" can indicate significant pulmonary disease 2
• Examine the lungs: Auscultate for decreased breath sounds, crackles, or pleural rubs 1
• Check vital signs: Fever, tachypnea, hypoxia, or tachycardia suggest systemic illness 1, 2
• Order chest imaging immediately: Chest X-ray is the first-line test when back pain worsens with breathing 1, 2

Step 2: Rule Out Life-Threatening Emergencies

The American College of Physicians emphasizes screening for conditions requiring prompt evaluation: 3, 4

• Pulmonary embolism: Particularly in patients on oral contraceptives or with other risk factors 1
• Aortic pathology: Dissection or rupturing aneurysm can present with back pain 5
• Spinal infection: Screen for fever, recent infection, IV drug use, or immunocompromised status 4

Step 3: Consider Musculoskeletal Causes Only After Excluding Pulmonary/Systemic Disease

If chest imaging and examination are normal, then consider:

• Rib fracture or costochondritis: Direct trauma history, point tenderness 6
• Intercostal muscle strain: Recent coughing, unusual physical activity 6
• Thoracic spine pathology: Vertebral compression fracture (assess for osteoporosis, steroid use, older age) 3, 4

Common Pitfalls to Avoid

• Do not diagnose "myogenic back pain" when pain worsens with breathing: This pattern demands investigation for pleuropulmonary causes first 1
• Do not dismiss subtle dyspnea: Progressive dyspnea that the patient minimizes can accompany serious pulmonary pathology presenting as back pain 2
• Do not delay imaging: When respiratory-pattern pain is present, obtain chest X-ray immediately rather than waiting for symptom evolution 1, 2
• Do not assume young age excludes serious pathology: Pulmonary embolism and pneumonia occur in young patients, especially with risk factors like oral contraceptive use 1

Red Flags Requiring Urgent Evaluation

The American College of Physicians identifies these features requiring prompt assessment: 3, 4

• History of cancer (increases probability from 0.7% to 9%) 4
• Unexplained weight loss 4, 2
• Fever or recent infection 4
• Progressive dyspnea, even if mild 2
• Failure to improve after one week, especially with new respiratory symptoms 1

When Standard Low Back Pain Guidelines Do NOT Apply

The American College of Physicians guidelines for nonspecific low back pain explicitly exclude patients with conditions outside the back such as pulmonary pathology. 3 Pain worsening with deep breathing places the patient outside the "nonspecific low back pain" category and requires evaluation for systemic or pleuropulmonary disease before applying standard back pain management. 3, 4