Clubbing is defined as the bulbous swelling of the distal ends of fingers or toes that results in loss of angle between the skinfold and the nail plate. Clubbing is characterized by connective tissue proliferation and edema as a result of which the nails become boggy. Clubbing of fingers is an acquired condition that can be due to many underlying conditions. CAUSES OF CLUBBING Thoracic causes: 1. Chronic suppurative conditions: Pulmonary tuberculosis, Bronchiectasis, lung abscess, empyema, cystic fibrosis, asbestosis, fibrosing alveolitis 2. Malignancies: lung cancer (except small cell carcinoma), mesothelioma, fibroma 3. Pulmonary fibrosis Cardiovascular causes: Cyanotic congenital heart disease, infective endocarditis, arteriovenous shunts and aneurysms. Gastrointestinal causes: Cirrhosis, celiac disease, inflammatory bowel disease Other causes: Thyrotoxicosis, primary hypertrophic osteoarthropathy