COPD differential diagnosis: evaluating suspected COPD

A COPD differential diagnosis starts with understanding the causes of shortness of breath (dyspnea) and knowing how to tell them apart. Many serious conditions can present with similar symptoms. Recognizing the key clinical features and choosing the right diagnostic tests is what turns a broad differential into the correct diagnosis.

In this lesson from our COPD Essentials course, you'll learn how to:

• Recognize anemia and cardiac causes of shortness of breath (dyspnea)
• Rule out pulmonary embolism
• Distinguish pneumonia, bronchiectasis, and tuberculosis from COPD
• Differentiate COPD vs asthma
• Use a spirometry test for COPD to confirm the diagnosis

COPD differential diagnosis: evaluating shortness of breath

[00:00]
The diagnosis of COPD requires you to differentiate it from other conditions with similar symptoms. Understanding the nuances of differing diagnoses is crucial for ensuring proper treatment and management of patients presenting with respiratory issues. The most common presenting symptom of COPD is shortness of breath. But there are many other important diagnoses to consider in such a case.

Anemia as a cause of shortness of breath

[00:30]
Whenever I think of exertional shortness of breath, I first think of anemia and its risk factors like gastrointestinal bleeding, heavy menstrual cycles, malnutrition, cancer, or the use of blood thinners. Fortunately, you can screen for anemia with a physical exam and blood work.

Heart attack and cardiac causes of dyspnea

[00:49]
Shortness of breath can also be the only presenting symptom of a heart attack, particularly in older patients, females, and those with poorly controlled diabetes. Blood work will show an elevated serum brain natriuretic peptide level, a biomarker for heart failure, as it's released when there is increased pressure in the heart. An electrocardiogram, or ECG, and troponin blood test can be used to confirm the diagnosis of a heart attack.

Ruling out pulmonary embolism

[01:21]
Similarly, shortness of breath, chest pain, swelling, and hypoxia can also suggest a possibility of pulmonary embolism. Typically, these patients present with tachycardia and have risk factors for, or evidence of, deep vein thrombosis. A D-dimer test has great sensitivity for screening for pulmonary embolism as it measures the presence of D-dimer, which is produced when blood clots dissolve in the body. A computed tomography or CT angiogram can definitively confirm this diagnosis.

Congestive heart failure vs COPD

[01:59]
Another common feature of COPD is edema with shortness of breath with exertion, but this sounds a lot like congestive heart failure. The distinguishing features of congestive heart failure are crackles on auscultation, suggesting fluid in the lungs, and a chest x-ray showing an enlarged heart and pulmonary edema.

Pulmonary infections in the COPD differential diagnosis

[2:20]
Cough and sputum production with shortness of breath should include the differential diagnosis of pneumonia, bronchiectasis, and tuberculosis. Patients with pneumonia often present with cough and fever. The physical exam and chest x-ray are specific to pneumonia.

Bronchiectasis and overlapping COPD symptoms

[2:38]
Bronchiectasis is a lung condition where the airways become damaged and permanently widened because of repeated infections and inflammation, making it hard to clear mucus. This creates an environment that breeds bacteria and can lead to frequent lung infections. Bronchiectasis can be caused by many things like cystic fibrosis, autoimmune disorders, gastroesophageal reflux, and immune deficiency leading to recurrent pneumonias. The suggestive feature of bronchiectasis is large amounts of purulent sputum and chest imaging showing bronchial dilation.

When to suspect tuberculosis 

[03:15]
And in the setting of a chronic cough, fatigue and weight loss, you have to think about tuberculosis. You should consider tuberculosis in areas of high prevalence. Findings of tuberculosis on a chest x-ray will show infiltrates, like a collection of pus, and scarring in the upper lung zones. But you will need microbiological confirmation to diagnose tuberculosis.

COPD vs asthma: key differences

[03:41]
Asthmatics also present with shortness of breath, chest tightness, wheezing and airflow obstruction. Often they've been diagnosed earlier in life, and there is a family history of asthma, along with allergy and skin symptoms like eczema. The symptoms of asthma vary from day to day, and are based on environmental triggers. This variation is reflected in the air flow obstruction, which is both variable and reversible.

Spirometry test for COPD vs asthma

[04:09]
If the differentiation is unclear, spirometry will distinguish between COPD and asthma. Importantly, asthma and COPD can coexist in the same patient. If a concurrent diagnosis of asthma is suspected, medication therapy should primarily follow asthma guidelines.

Confirming COPD

[04:29]
As a matter of fact, please recognize that patients can have COPD and congestive heart failure, pulmonary embolism, anemia, heart attack, asthma, or pneumonia all at the same time. When evaluating the differential diagnosis of COPD symptoms, your tools include chest x-ray, ECG, blood work, and ultimately spirometry, to confirm that there is fixed airflow obstruction.