Chronic obstructive pulmonary disease, or COPD, refers to a group of lung diseases that causes limited airflow in and out of the lungs. COPD reduces the amount of oxygen that goes into the blood, and less oxygen makes it difficult for the heart to pump. COPD usually progresses gradually, and people may develop it from environmental factors or as an inherited disorder.
Cigarette Smoking
According to MayoClinic.com, long-term cigarette smoking causes most cases of COPD because of the irreversible lung damage that results. Cigarette smoke irritates and inflames the airways and the inflammation narrows the airways, making it more difficult to breathe. Cigarette smoke also restricts the cilia--the hair-like structures located in the respiratory tract that move back and forth, pushing out foreign matter--from working properly, reports the Cleveland Clinic. Mucus and particles such as air pollution, dust and occupational fumes stay trapped in the airways and people who smoke experience more bouts of chronic lung infections as a result.
Alpha-1 Antitrypsin Deficiency
The National Heart, Lung and Blood Institute explains that alpha-1 antitrypsin deficiency, or AAT deficiency, typically occurs as an inherited disorder and many people who have the condition don’t know they have it. The liver releases alpha-1 antitrypsin proteins into the bloodstream and they help protect the lungs and other organs from the harmful effects that the body’s other proteins produces. AAT deficiency results when the alpha-1 antitrypsin proteins that the liver normally makes aren’t made in the right shape. Their irregular shape causes them to get stuck inside the liver cells and they can't get into the bloodstream to circulate throughout the body. Serious lung diseases develop because not enough AAT proteins travel to the lungs to protect them. People with AAT deficiency increase their risk for developing COPD and other lung diseases if they smoke.
Emphysema
COPD primarily refers to obstruction in the lungs from two chronic lung conditions and people with COPD usually have both, states MayoClinic.com. One of the chronic lung conditions called emphysema, causes destruction to the walls of the alveoli, or air sacs, located at the end of the bronchioles--the smaller tubes that branch off of the bronchi. A person with damaged alveoli cannot receive oxygen when they breath in air and they cannot release carbon dioxide when they breath out air. The bronchioles lose their elasticity and they collapse during exhalation, trapping air in the lungs. The air trapped in the lungs, along with the impaired oxygen and carbon dioxide exchange, results in less oxygenated blood throughout the body.
Chronic Bronchitis
The Cleveland Clinic notes that chronic bronchitis causes ongoing irritation and inflammation of the lining in the bronchial tubes, or air passages. The irritation causes coughing and an excess amount of mucus forms in the airways as a result. The inflammation results in narrowed bronchial tubes, and narrowed bronchial tubes along with increased mucus production makes it difficult for air to enter into the lungs and then exit out of the lungs.
