Alternative Names COPD, chronic obstructive airways disease (COAD)
Definition Chronic obstructive pulmonary disease (COPD) is a chronic lung disease that reduces the ability to breathe. Chronic bronchitis and emphysema are two common types of COPD. Chronic bronchitis is present when a person has a cough and produces sputum on most days for at least three months a year for two years in a row. Other causes for chronic cough, such as lung infections or tumours, need to be excluded before the diagnosis of chronic bronchitis is made. Emphysema is present when many of the air sacs in the lung are destroyed and the air sacs left over are abnormal and have poor function.
What is going on in the body? Over years of exposure to cigarette smoke or dust, damage to the windpipe or smaller airway tubes and lungs may result. The respiratory or breathing system tries to protect against damaging substances in the air by making extra mucous. However, the lungs may slowly get damaged from chronic irritation. The increased mucous and lung damage can be permanent.
What are the signs and symptoms of the disease? Typical symptoms of COPD are cough, phlegm production and shortness of breath. Some people develop gradual exercise limitation but cough only infrequently. Others have a chronic, moist cough, and have frequent chest colds. During colds, shortness of breath may get much worse. Some have wheezing, particularly when there is acute bronchitis, or inflammation of the airway tubes. The lungs can take a lot of damage before difficulty with exercise is noticed. When the disease is advanced, even minimal activities like getting dressed are difficult because of shortness of breath. In some people, the heart is weakened and there is swelling of the feet and legs. Many develop a low blood oxygen level at some point during the disease. This may require supplemental oxygen to be given by nose or mouth.
What are the causes and risks of the disease? Cigarette smoking is the most common cause of COPD. The risk goes up with the amount of tobacco smoked, and the number of years of smoking. Chronic bronchitis occurs in the majority of cigarette smokers. Significant COPD occurs in only 15 to 20 percent of smokers. Exposure to tobacco smoke, mineral dusts, chemicals and some infections are also risk factors. Genetic factors make some more likely to develop COPD. Screening blood tests are available and treatment exists.
The primary risk of COPD is a restriction of activities due to a decreased ability to exercise. The risk of death is also increased in those with COPD.
What can be done to prevent the disease? Avoidance of smoking will prevent the disease in most people. Dusty areas should be evaluated for COPD risk. Work practices and workplace design to reduce chemical and dust exposure can help prevent COPD.
How is the disease diagnosed? The disease is suspected by the history of shortness of breath and cough. A test called spirometry, which measures lung and breathing function, can confirm the diagnosis. A plain or other special x-ray test may be done to exclude other causes of shortness of breath and cough.
What are the long-term effects of the disease? The long-term effects depend on how severe the COPD is when diagnosed and if a reduced exposure to the lung irritant occurs. The most effective treatment is Quitting smoking. This will typically result in a modest improvement or no further decline in function. People with COPD have a higher mortality than those with normal lung function. Causes of death include respiratory failure, lung infections such as pneumonia and influenza, and other diseases related to smoking. These include cancer, heart disease, and stroke.
What are the risks to others? COPD is not contagious. However, people who live with smokers have significant health risks because of their exposure to the smoke.
What are the treatments for the disease?
quitting smoking is the leading treatment. There is help for those who want to quit, including medications to decrease withdrawal and increase the chance of successful quitting. Examples include nicotine replacement therapy, using a patch, gum or inhaler, and bupropion
A pneumonia and flu vaccination may help prevent common complicating infections.
Medications delivered by an inhaler or "puffer" may improve lung function and quality of life.
Corticosteroids, such as prednisone, may be given to reduce inflammation in the lungs
Oxygen therapy prolongs life and improves the quality of life for those with low oxygen levels.
Pulmonary rehabilitation uses teaching and exercise to improve function. It has benefits for those with COPD.
What are the side effects of the treatments? Stopping smoking may result in symptoms of nicotine withdrawal. These include:
Nicotine replacement decreases these side effects, but may cause toxic effects if a person continues to smoke while taking it. Buproprion should not be taken if there is a history of seizures.
Inhalers may cause an increased heart rate and blood pressure.
Oral corticosteroids can have many side effects including:
Oxygen therapy can be cumbersome. Tubing must be worn and an oxygen tank is carried. Some people develop dry nasal passages and may have minor nosebleeds.
Pulmonary rehabilitation can be difficult for those with arthritis or uncontrolled heart disease.
What happens after treatment for the disease? The response to treatment is variable. Some improve to the point that they have no symptoms or limitations of daily activities. Some deteriorate despite treatment. In the middle are those who are able to decrease, but not eliminate, symptoms. These people may have occasional acute periods of increased symptoms.
How is the disease monitored? Symptoms and physical examination are followed. Spirometry is often used to monitor COPD. Each individual has a certain level of lung function. Lung function can be compared to standards for age, sex and height. In healthy people, lung function is stable. It decreases less than 1 percent per year in adult life. Declines in lung function of more than 10 percent per year show a need to consider if an individual's exposure profile should be changed.
Author: Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
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