pulmonary disease, any abnormal condition of the respiratory system, characterized by cough, chest pain, dyspnea, hemoptysis, sputum production, stridor, or adventitious sounds. Less common symptoms include anxiety, arm and shoulder pain, tenderness in the calf of the leg, erythema nodosum, swelling of the face, headache, hoarseness, joint pain, and somnolence. Diagnostic procedures for pulmonary diseases include bronchoscopy; cytological, serological, and biochemical examination of bronchial secretions; laryngoscopy; pulmonary function tests; and radiography. Obstructive respiratory disease is the result of a reduction of airway size that impedes airflow. The obstruction may result from bronchospasm, edema of the bronchial mucosa, or excessive bronchial secretions. Obstructive disease is characterized by reduced expiratory flow rates and increased total lung capacity. Acute obstructive respiratory diseases include asthma, bronchitis, and bronchiectasis; chronic obstructive diseases include emphysema, chronic bronchitis, or combined emphysema and chronic bronchitis. Patients with obstructive diseases may have acute respiratory failure from any respiratory stress, such as infections or general anesthesia. Restrictive respiratory disease is caused by conditions that limit lung expansion, such as fibrothorax, obesity, a neuromuscular disorder, kyphosis, scoliosis, spondylitis, or surgical removal of lung tissue. Pregnancy causes a self-limiting restrictive disease in the third trimester. Characteristics of restrictive respiratory disease are decreased forced expired vital capacity and total lung capacity, with increased work of breathing and inefficient exchange of gases. Acute restrictive conditions are the most common pulmonary cause of acute respiratory failure. Infectious diseases include pneumonia and tuberculosis.