lung and airway disorders
Chronic Obstructive Pulmonary Disease (COPD)
Introduction
Chronic obstructive pulmonary disease is persistent narrowing (blocking, or obstruction) of the airways occurring with emphysema, chronic obstructive bronchitis, or both disorders. Cigarette smoking is the most important cause of chronic obstructive pulmonary disease. People develop a cough and eventually become short of breath. Diagnosis is made with chest x-rays and tests of lung function. Stopping smoking and taking drugs that help keep airways open are important. People who have severe disease may need to take other drugs, use oxygen, have pulmonary rehabilitation, or rarely lung volume reduction surgery. In the United States, about 16 million people have chronic obstructive pulmonary disease (COPD). It is a common cause of death, accounting for more than 150,000 each year. Worldwide, the number of people with COPD is increasing. Factors contributing to COPD include an increase in smoking in many countries and, throughout the world, exposure to toxins in biomass fuels such as wood and grasses. Death rates may be increasing in medically underserved countries. By 2030, COPD is projected to become the third leading cause of death worldwide. COPD leads to a persistent decrease in the rate of airflow from the lungs when the person breathes out (exhales), which is called chronic airflow obstruction. COPD includes the diagnoses of chronic obstructive bronchitis and emphysema. Many people have both disorders. Chronic bronchitisis defined as cough that produces sputum for at least 3 months during two successive years. When chronic bronchitis involves airflow obstruction, it qualifies as chronic obstructive bronchitis. Emphysemais defined as widespread and irreversible destruction of the alveolar walls (the cells that support the air sacs, or alveoli, that make up the lungs) and enlargement of many of the alveoli. Chronic asthmatic bronchitis is similar to chronic bronchitis. In addition to having a cough that produces sputum, people have Wheezing and partially reversible airflow obstruction. It occurs predominantly in people who smoke and have The small airways (bronchioles) of the lungs contain smooth muscles and are normally held open by their attachments to alveolar walls. In emphysema, the destruction of alveolar wall attachments results in collapse of the bronchioles when a person exhales, causing airflow obstruction that is permanent and irreversible. In chronic bronchitis, the glands lining the larger airways (bronchi) of the lungs enlarge and increase their secretion of mucus. Inflammation of the bronchioles develops and causes smooth muscles in lung tissue to contract (spasm), further obstructing airflow. Inflammation also causes swelling of the airway passages and secretions in them, further limiting airflow. Eventually, the small airways in the lung become narrowed and destroyed. Asthma is also characterized by airflow obstruction. However, unlike airflow obstruction in COPD, airflow obstruction in asthma is completely reversible in most people, either spontaneously or with treatment. Airflow obstruction in COPD causes air to become trapped in the lungs after a full exhalation, increasing the effort required to breathe. Also in COPD, the number of capillaries in the walls of the alveoli decreases. These abnormalities impair the Exchanging Oxygen and Carbon Dioxide between the alveoli and the blood. In the earlier stages of COPD, oxygen levels in the blood may be decreased, but carbon dioxide levels remain normal. In the later stages, carbon dioxide levels increase and oxygen levels fall. The COVID-19 pandemic has posed a particular risk to people with COPD. Having COPD increased a person's risk of being hospitalized or dying from COVID-19. Overall, however, people with COPD were hospitalized less often during the COVID-19 pandemic than before. Increased precautions against respiratory infection (for example, masks, social distancing) are thought to be why people with COPD were hospitalized less. Also, people with symptoms, such as an acute exacerbation of COPD, may have avoided their local emergency department out of fear of contracting COVID-19. 