What are the diagnostic tests and laboratory evaluations for dyspnea (shortness of breath) on exertion?

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Last updated: March 24, 2025 • View editorial policy

From the Guidelines

Dyspnea on exertion should be evaluated with a combination of physical examination, laboratory tests, and functional assessments, including complete blood count, comprehensive metabolic panel, BNP or NT-proBNP, thyroid function tests, pulmonary function tests, chest X-ray, electrocardiogram, and exercise testing, as recommended by the most recent guidelines 1. The initial workup for dyspnea on exertion should include:

  • Complete blood count to assess for anemia
  • Comprehensive metabolic panel to evaluate organ function
  • BNP or NT-proBNP to screen for heart failure
  • Thyroid function tests to rule out thyroid disorders
  • Pulmonary function tests, including spirometry with bronchodilator response, lung volumes, and diffusion capacity, to evaluate for obstructive or restrictive lung diseases
  • Chest X-ray and electrocardiogram to assess cardiac and pulmonary structures Exercise testing is particularly valuable, with the 6-minute walk test providing a simple assessment of functional capacity, while cardiopulmonary exercise testing offers comprehensive evaluation of cardiovascular, pulmonary, and muscular systems by measuring oxygen consumption, carbon dioxide production, and ventilatory parameters during incremental exercise 2. In selected cases, additional tests like echocardiogram to evaluate cardiac function, CT scans of the chest for detailed lung imaging, or sleep studies to rule out sleep-disordered breathing may be indicated based on clinical suspicion, as suggested by the American College of Radiology 3. These tests collectively help determine whether dyspnea is cardiac, pulmonary, deconditioning-related, or due to other systemic conditions, and guide further management and treatment, ultimately improving morbidity, mortality, and quality of life for patients with dyspnea on exertion.

From the Research

Diagnostic Tests for Dyspnea

The diagnostic tests for dyspnea (shortness of breath) on exertion include:

  • Cardiopulmonary exercise testing to differentiate cardiac and respiratory limitation, document deconditioning, and identify psychogenic dyspnea 4
  • Measurement of dyspnea and leg discomfort during exercise testing using the Borg 0 to 10 category-ratio scale or the visual analog scale 4
  • Chest radiographs, electrocardiograph, and screening spirometry to provide valuable information 5
  • Complete pulmonary function testing, arterial blood gas measurement, echocardiography, and standard exercise treadmill testing or complete cardiopulmonary exercise testing for inconclusive or unclear results 5
  • Right heart catheterization at rest and during exercise to allow for exact differentiation 6

Laboratory Evaluations

Laboratory evaluations for dyspnea include:

  • Basic findings such as physical examination, electrocardiogram (ECG), spirometry, and laboratory tests to help with diagnosis 6
  • First-line tests including a complete blood count, basic chemistry panel, electrocardiography, chest radiography, spirometry, and pulse oximetry 7
  • Second-line noninvasive testing such as echocardiography, cardiac stress tests, pulmonary function tests, and computed tomography scan of the lungs if no cause is identified 7
  • Invasive tests such as ventilation perfusion scans, Holter monitoring, cardiac catheterization, esophageal pH monitoring, lung biopsy, and cardiopulmonary exercise testing for unclear diagnoses 8

Approach to Diagnosis

The approach to diagnosing dyspnea involves:

  • A thorough patient history to establish a preferred differential diagnosis 6
  • A combination of symptoms, clinical signs, and findings to guide the selection of initial diagnostic tests 6
  • A staged approach to testing, beginning with first-line tests and progressing to second-line and invasive tests as needed 7, 8
  • Collaboration with specialty help for invasive tests and multidisciplinary approach to care 7

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.