Chronic Obstructive Pulmonary Disease: The Basics
What Is COPD?
Chronic obstructive pulmonary disease (COPD) affects many individuals across Alberta. According to Alberta Health Services, COPD was the sixth leading cause of death but is expected to increase to the third by this year. It is a progressive disease of the lungs, where inflammation and increased mucus production cause obstruction of the airflow. The two most common conditions that contribute to COPD are chronic bronchitis and emphysema. Chronic bronchitis is a persistent cough that causes inflammation of the airways, overproduction of mucus, and frequent infections. With emphysema, the tiny structures in the lungs responsible for gas exchange become increasingly damaged, so carbon dioxide and oxygen exchange is impaired. COPD is caused by continuous exposure to irritants, such as cigarette smoke, over a long period of time. Those with COPD have an increased risk of developing many other serious health conditions, including lung cancer. The following are risk factors that contribute to the development of COPD: age over forty years, and exposure to first- and second-hand cigarette smoke, chemicals, burning fuels, pollution, and dust. In order to understand COPD, it is essential to first have a basic understanding of lung anatomy and physiology.
A Closer Look at the Lungs
Our lungs are the pair of organs in the thoracic cavity (chest) that are responsible for our body’s exchange of oxygen and carbon dioxide. The right lung is made up of three lobes and the left lung is made up of two lobes to allow space for the heart. The rest of the respiratory system consists of the trachea (windpipe), bronchi (tubes connecting the lungs to the trachea), bronchioles (smaller branches of the bronchi), and alveoli (tiny sacs of air at the end of each bronchiole). Each alveolus is covered with tiny blood vessels (capillaries) and this is where oxygen and carbon dioxide exchange occurs. There are approximately six hundred million alveoli in our lungs, and since they are spherically shaped, they provide a massive amount of surface area for oxygen exchange — comparable to the size of a tennis court! Air enters our body through our nose or mouth, travels through the trachea, passes through the bronchi and bronchioles, and finally to the alveoli. Our alveoli inflate and expand when we inhale, and deflate but stay partially inflated during exhalation. Our lungs create surfactant — a lubricating fluid containing fatty proteins — which eases the inflation of our alveoli. Our lungs also create mucus to trap germs and foreign particles.
How COPD Affects the Respiratory System
The chronic exposure to irritants leading up to the development of COPD causes the airway to become inflamed and obstructs the otherwise effortless passage of air. Airway obstruction eventually causes more and more air to become trapped in the lungs during exhalation. This trapped air hyperinflates the lungs and then limits the amount of air that can be inhaled. Air trapping continues over time and the volume of air left in the lungs after a normal breath increases. This is why individuals with COPD often experience shortness of breath during strenuous exercise. The chronic irritation also causes the tissues of the lungs, especially the alveoli, to lose their elastic property — otherwise known as ‘compliance.’ In addition to reduced elasticity, COPD results in a dangerous combination of overproduction of mucus and a reduced ability to clear it. This will lead to excessive coughing and difficulty breathing. This means that it will be difficult for air to reach the alveoli to complete the gas exchange, and the saturation of oxygen in the blood will decrease. There is currently no known cure, but there are treatments that can slow the progression of the disease, so it is vital to be aware of the risk factors and symptoms and see your doctor regularly.
This article took information from several reliable websites including HealthLine.com, the Canadian Institute for Health Information, MedicineNet.com, AlbertaHealthServices.ca, and VeryWellHealth.com.
By Rachel Hughes, RN
ARTACares is provided by HumanaCare, an Alberta-based health and wellness provider with more than thirty-five years of Canadian health care experience.