With chronic obstructive airways disease (COAD), there is ongoing blockage of the airways caused by emphysema or chronic bronchitis.
Sometimes, asthma and COAD will occur together. It is also possible that if you have asthma that is not fully controlled, repeated attacks over many years may themselves lead to COAD.
What is Emphysema?
Emphysema destroys the tiny air sacs in the lungs (alveoli), and the walls of the alveoli lose their elasticity and enlarge. As they enlarge, the diaphragm flattens, making it harder for the lungs to move air both in and out. It makes it difficult for the lungs to absorb enough oxygen or to expel enough carbon dioxide. As the lungs can’t repair the air sacs when they are destroyed, the damage is permanent.
The main symptom of emphysema is shortness of breath which gradually becomes more severe over many years. The damage to the lungs has however, been going on for a long time before you feel breathless. In the early stages there are no symptoms, and you may think it starts suddenly.
While some people with emphysema don’t have a problem with a cough or mucus, others find it very hard to dislodge mucus (phlegm) from their lungs.
What about bronchitis?
The second main cause of blockage of airflow is inflammation of the small airways in chronic bronchitis. This causes scarring of the walls of the airways, swelling in the lining, partial blockage of the air passages by mucus, and spasm of the smooth muscle. The swelling, mucus blockage and smooth muscle spasm can vary in severity from time to time. It may improve with “reliever” medication.
All forms of COAD cause air to be trapped in the lungs, with the number of tiny blood vessels in the air sacs decreasing. These changes impair the exchange of oxygen and carbon dioxide. In the earlier phases of the disease, the levels of oxygen in the blood are less, but carbon dioxide levels remain normal. In later stages, carbon dioxide levels rise, and blood oxygen levels fall even further.
What causes emphysema and chronic bronchitis?
By far the most common cause of emphysema and chronic bronchitis is smoking. Also, the disease progresses much faster in people who carry on smoking than those who give up. People ask why some get COAD and others do not. We don’t know why, as some are more susceptible than others.
Doctors can’t predict who will get COAD, but they do know who is at higher risk. Other risk factors include:
• passive smoking
• air pollution
• an inherited condition called “Alpha-1-protease inhibitor deficiency” - a natural substance in the blood which protects your lungs from smoke, pollution, dust and infections. If you lack this you may eventually suffer severe emphysema.
What are the symptoms of COAD?
The earliest symptom (which may appear after as little as 5-10 years of smoking), is a cough and phlegm, most often when getting up in the morning. The cough is generally mild and many people call it a “smokers cough”. There is also a tendency for colds to settle on the chest. During chest colds, the phlegm often becomes yellow or green because of infection. As years go by, chest colds come more often. There may also be wheezing.
By the age of 60, many people with COAD have shortness of breath on effort. This may eventually impact on your activities of daily living such as showering and dressing.
About one third of people with COAD have weight loss and some may develop swelling of the legs.
How is COAD diagnosed?
In mild COAD, the physical exam by your doctor may reveal little apart from a few wheezes. A breathing test will show the degree of airway blockage. This is a simple test, quite painless. In a person with COAD, the test shows reduced airflow when you exhale air
Your doctor may also want to measure the amount of oxygen in your blood. This is a simple routine test. The less oxygen in your blood, the more severe is the COAD.
Once your condition is diagnosed, your doctor may prescribe medication to help control your symptoms. If you are not getting enough oxygen to your blood, your doctor may prescribe oxygen. You will be referred to a company that provides home health care services. This company will deliver your oxygen and show you how to use it.
What can you do about COAD?
By far the most important way to slow down the progress of COAD is to STOP SMOKING. If you stop smoking, the disease will slow down. It won’t stop entirely.
You can learn to breathe better, for example with “pursed-lip” breathing and “diaphragmatic” breathing. You can help prevent lung infections and shortness of breath by keeping your lungs free of mucus. You can do this with controlled coughing and postural drainage. You do this by lying in certain positions which allow gravity to drain excess mucus from your lungs.
Regular exercise will build your strength and endurance safely and slowly while doing things you enjoy.
What you eat can affect how you breathe and how well you feel. Maintain a healthy weight, drink lots of fluids to keep mucus thin and eat a balanced diet.
If you get a cold or flu, make sure you seek medical treatment early. Also seek treatment if you have:
• fever or chills
• chest tightness that doesn’t go away with normal medication
• increased coughing, wheezing or shortness of breath
• increased blood in your mucus, mucus with odour or that is green or yellow
• swollen ankles
• irregular pulse
Berkow, R (1997) The Merck Manual of Medical Information, Merck Research Laboratories, N.J.
Hart, D (1992)Chronic Bronchitis and Emphysema, Victorian Tuberculosis and Lung Association (Booklet)
Krames (1995) Chronic Obstructive Pulmonary Disease, CA (Booklet)
Written & reviewed by the Respiratory Team, 2M, the Wesley Hospital, 2006.
Disclaimer: This information is intended as a guideline only and reflects the consensus of the authors after a literature review. The sources used are believed to be reliable and in no way replace consultation with a Health Professional.