Dyspnoea/breathlessness is defined as a “subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity”1. Pulmonary causes include obstructive, restrictive, alveolar and airway pathologies. The most common obstructive causes are chronic obstructive pulmonary disease (COPD) and asthma. Restrictive lung disease includes extra–pulmonary etiologies like obesity, spinal deformities or chest wall deformities, and intrinsic pulmonary etiologies such as interstitial lung disease, interstitial fibrosis, pneumoconiosis, granulomatous disease or collagen vascular disease. Alveolar pathologies include chronic pneumonia and broncho–alveolar carcinoma. Airway diseases include chronic bronchitis and bronchiectasis2, 3.In our study we excluded non respiratory causes like cardiac, neurogenic, metabolic causes & patients with neoplastic lung mass. In a suspected pulmonary pathology as a cause of breathlessness, a chest–X ray is often the first radiological investigation. The conventional chest X–ray is cheap and easily accessible but limited in scope and sensitivity. High–resolution thin section (HRCT) is far superior for detection, characterization and demonstration of the pulmonary interstitium, air spaces and airways4.In our study done on 80 patients, HRCT is recognized as more sensitive and specific than chest radiography for the evaluation of patients with breathlessness.