From the Guidelines
For a healthy 50-year-old experiencing dyspnea on exertion, the most likely cause is a cardiac or pulmonary issue, and a comprehensive evaluation including laboratory tests and functional assessments is necessary to determine the underlying cause, as suggested by the most recent study 1. The evaluation should include initial laboratory tests such as:
- Complete blood count to check for anemia
- Comprehensive metabolic panel to assess kidney and liver function
- Thyroid function tests
- B-type natriuretic peptide (BNP) to evaluate for heart failure Additional tests should include:
- Chest X-ray to examine lung fields and heart size
- Electrocardiogram (ECG) to assess cardiac rhythm and evidence of ischemia
- Pulmonary function tests to evaluate for obstructive or restrictive lung disease
- Echocardiogram to assess cardiac structure and function Exercise stress testing is particularly valuable to reproduce symptoms and evaluate cardiopulmonary response to exertion, as recommended by the American Heart Association 1. In some cases, additional specialized tests may be necessary, such as:
- Cardiopulmonary exercise test to measure oxygen consumption during exercise
- CT imaging of the chest to evaluate for interstitial lung disease or pulmonary embolism This comprehensive approach is important because dyspnea on exertion in an otherwise healthy middle-aged adult could stem from cardiac, pulmonary, hematologic, or metabolic causes, and proper diagnosis requires systematic evaluation of these potential etiologies. The diagnostic evaluation should be centered around careful history taking and physical examination, and may be supplemented by diagnostic investigation such as chest radiography and electrocardiography (ECG) as well as laboratory testing, as suggested by the ACR Appropriateness Criteria 1. Advanced diagnostic imaging may play a critical role in the care of patients with unexplained dyspnea, and directed follow-up of findings is necessary to establish a specific diagnosis, as recommended by the American Heart Association 1.
From the Research
Causes of Dyspnea
- Dyspnea, or shortness of breath, can be caused by a variety of factors, including asthma, heart failure, myocardial ischemia, chronic obstructive pulmonary disease, interstitial lung disease, pneumonia, and psychogenic disorders 2, 3.
- The etiology of dyspnea is often multifactorial, with about one-third of patients having multiple underlying causes 2.
- A thorough patient history, physical examination, and basic laboratory tests, such as chest radiography, electrocardiography, spirometry, and complete blood count, are essential in evaluating dyspnea 2, 3, 4.
Diagnostic Approach
- The diagnostic approach to dyspnea typically involves a step-wise approach, starting with first-line tests, such as complete blood count, basic chemistry panel, electrocardiography, chest radiography, spirometry, and pulse oximetry 3.
- If no cause is identified, second-line noninvasive testing, such as echocardiography, cardiac stress tests, pulmonary function tests, and computed tomography scan of the lungs, may be necessary 3.
- In some cases, more invasive tests, such as right heart catheterization or bronchoscopy, may be required to diagnose underlying conditions, such as pulmonary arterial hypertension or interstitial lung disease 2, 4, 5.
Specific Conditions
- Interstitial lung disease (ILD) is a known cause of dyspnea, and patients with ILD may present with worsening dyspnea on exertion 5, 6.
- Pulmonary arterial hypertension is another condition that can cause dyspnea, and right heart catheterization may be necessary to diagnose this condition 5.
- COVID-19 can also exacerbate underlying lung conditions, such as ILD, and lead to worsening dyspnea 6.