Bilateral and Symmetrical Dark Lungs

CLINICAL DIAGNOSTIC MANUAL

Bilateral and symmetrical dark lungs on a chest X-ray indicate increased pulmonary hyperlucency, which reflects an increased amount of air present in the lungs.

This finding is common in chronic obstructive pulmonary diseases, where the lungs have a reduced capacity to expel air, resulting in hyperinflation. The most common conditions associated with this radiological pattern are chronic obstructive pulmonary disease (COPD) and asthma.

Pathology	Clinical Symptoms and Signs	Suspected Diagnosis	Confirmatory Diagnosis
Chronic obstructive pulmonary disease (COPD)	Chronic dyspnoea, productive cough, wheezing, fatigue, cyanosis	History of smoking, chronic symptoms	Chest X-ray, spirometry, chest CT, arterial blood gases
Asthma	Episodic dyspnoea, wheezing, cough, chest tightness, especially at night	History of episodic symptoms, triggering factors	Spirometry with bronchodilator test, bronchoprovocation test, chest X-ray for atypical cases
Bronchiectasis	Chronic productive cough, purulent sputum, recurrent respiratory infections	History of recurrent respiratory infections, chronic symptoms	Chest X-ray, high-resolution chest CT, pulmonary function tests
Chronic obstructive disorders	Dyspnoea, cough, wheezing, fatigue	History of risk factor exposure, chronic symptoms	Chest X-ray, chest CT, spirometry, arterial blood gases