Respiratory Conditions Update: Restrictive Lung Disease.

Restrictive lung diseases are a heterogeneous group of conditions characterized by a restrictive pattern on spirometry and confirmed by a reduction in total lung volume. Patients with more severe symptoms may have a reduced diffusing capacity of the lung for carbon monoxide. Etiologies can be intrinsic with lung parenchymal involvement, as in interstitial lung diseases, or extrinsic to the lung, as in obesity and neuromuscular disorders.

Respiratory Conditions Update: Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease (COPD) is defined as persistent airflow limitation due to irritant-induced chronic inflammation. A postbronchodilator forced expiratory volume in 1 second to forced vital capacity (FEV1/FVC) ratio of 0.7 or less is diagnostic in a patient with dyspnea, chronic cough or sputum production, and a history of irritant exposure.

Respiratory Conditions Update: Asthma.

Asthma is a chronic respiratory disease characterized by chronic airway inflammation and variable expiratory airflow limitation. Related clinical features include wheezing, dyspnea, chest tightness, and cough that worsens at night or in the early morning, and that varies over time and in intensity. A finding of variable expiratory airflow limitation on spirometry confirms the diagnosis.