Because respiratory diseases like asthma and COPD share many common symptoms, people often confuse the two conditions. In fact, several adults who actually suffer from COPD have been mistakenly diagnosed with asthma.
Both asthma and COPD (Chronic Obstructive Pulmonary Disease) are respiratory diseases characterized by obstruction to the airway, but asthma is typically diagnosed in childhood, while COPD is usually diagnosed in adults over 40 with a history of smoking. Although many of the symptoms are similar, asthma can be distinguished by the dryness of cough; with COPD, the cough is more “productive” or mucus-yielding. Also, asthma symptoms disappear between episodes, but COPD symptoms progressively worsen instead.
|Introduction||Asthma is a common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm.||Chronic obstructive pulmonary disease (COPD) is a type of obstructive lung disease characterized by chronically poor airflow.|
|Symptoms||Chronic coughing; wheezing; shortness of breath; chest tightness; spasms in bronchioles. Symptoms go away between episodes.||Decreased airflow; increased inflammation; spasms in bronchioles; morning cough with phlegm. Symptoms never disappear, but progressively worsen.|
|Nature of cough||Dry||“Productive” (yields mucus)|
|Diagnosis||Physical exam, medical history including history of allergies Typically in children||Spirometry, measuring of breath CT scans Typically in adults over 40 Current or former smokers|
|Classical Presentation||Younger patient, recurrent episodes of wheezing and coughing, accompanying tight chest and breathlessness. Symptoms quickly respond to bronchodilators.||Older patient, smoker or former smoker, progressive shortness of breath and cough with mucus, accompanied by decreased physical activity. Responds to bronchodilator, but lung function does not return.|
|Triggers||Allergens, cold air, exercise||Environmental pollutants, respiratory tract infections – pneumonia, influenza|
|Risk Factors||Allergies, eczema, rhinitis||Asthma, smoking|
|Medical Treatment||Bronchodilators, Airway opening medication; Inhaled corticosteroids reduce inflammation; Oral steroids for moderate to severe cases||Bronchodilators; Airway opening medication; Pulmonary rehabilitation Oxygen support for advanced stages; Hospitalization|
|Lifestyle Changes||Cease smoking; avoid allergens and air pollution||Cease smoking; avoid air pollution|
Cause and Symptoms
Asthma causes and symptoms
Asthma is a condition of the narrowing of airways caused by inflammation (swelling) or excess mucus in the airways. When an asthma attack occurs, the lining of the air passages swells and the muscles surrounding the airways become tight. This reduces the amount of air that can pass through the airway. Typical symptoms include chronic coughing, wheezing, shortness of breath, and chest tightness (usually caused by spasms in the bronchioles). The nature of cough is dry. Symptoms go away between asthmatic episodes.
What causes asthma?
In April 2015, scientists from Cardiff University announced a breakthrough discovery of the potential root cause of asthma. Researchers found that environmental triggers — such as allergens, cigarette smoke and car fumes — release chemicals that activate CaSR (calcium sensing receptor) in airway tissue and drive asthma symptoms like airway twitchiness, inflammation, and narrowing.
The research also points to promising new treatment for asthma. Calcilytics, a class of drugs previously used to treat osteoporosis, can deactivate CaSR and prevent asthma symptoms. The drugs need to be nebulized directly into the lungs for them to work.
COPD causes and symptoms
COPD (Chronic Obstructive Pulmonary Disease) is a set of progressive respiratory diseases. In the US, emphysema and chronic bronchitis are considered types of COPD. The main cause of COPD is long-term exposure to substances that irritate and damage the lungs. This is usually cigarette smoke, although air pollution, chemical fumes or dust are also known to cause it.
COPD symptoms include decreased airflow, increased inflammation in the lungs, spasms in bronchioles and a morning cough with phlegm. Unlike asthma, the cough is "productive," i.e., it yields mucus. Again, unlike asthma, symptoms of COPD never disappear -- they just progressively worsen.
A further explanation of asthma and COPD is in the video below:
Doctors diagnose asthma during a physical exam. They take into consideration the patient's medical history, including allergies. Asthma classically presents in younger patients with recurrent episodes of wheezing and coughing. The symptoms include a tight chest and breathlessness. The symptoms quickly respond to bronchodilators.
COPD is also diagnosed during a physical exam. However, when COPD is suspected, they conduct spirometry, (measurement of breath), and at times CT scans. COPD typically occurs in patients over 40, and those who smoke or used to smoke. They suffer from progressive shortness of breath and cough with mucus. Their physical activity typically decreases. The symptoms respond to bronchodilators, but lung function does not return.
Triggers and Risk Factors
Asthma is more prone to worsening by triggers than is COPD. Allergens, cold air and exercise trigger asthma. A history of allergies, eczema, and rhinitis, or irritation of the nose's mucus membranes are the known risk factors.
COPD sufferers are still susceptible to triggers. COPD is exacerbated by environmental pollutants and respiratory tract infections such as pneumonia and influenza. People with asthma are more likely to develop COPD, as are smokers. In fact, COPD is almost always caused by smoking.
Asthma can be prevented in children (as subsequently as adults) by practicing some of the following:
- Breastfeeding infants for at least 6-8 months
- Reducing contact with pollen, allergens and dust mites in the early years
- Using zippered, "allergen-impermeable" covers on pillows and mattresses; washing bedding weekly with hot water
- Keeping children protected from active (during pregnancy) or passive tobacco smoke
COPD can be prevented significantly by
- Avoiding smoking and being exposed to tobacco smoke
- Staying away from dust, pollen and other allergens
- Avoiding close contact with strong chemicals or working in chemical plants
- If allergic to dust, keeping the house free of dust mites and preferably carpets
Both asthma and COPD respond to bronchodilators, or airway opening medication. However, asthma treatment usually includes inhaled corticosteroids to reduce inflammation. Sufferers may also need oral steroids for moderate to severe cases. COPD treatment includes pulmonary rehabilitation. Oxygen support and hospitalization may be necessary for advanced stages.
Both conditions necessitate lifestyle changes. Putting a stop to smoking is the biggest modification doctors recommend. People with asthma should avoid allergens and air pollution. People with COPD should avoid environmental air pollution. Air filters can help in both cases.
Effects and Coexisting Conditions
Asthma has several effects on the body. During an asthma attack, bronchial muscles constrict. The bronchial tubes spasm in response to allergens, which increases inflammation. While lung function does decrease, it can be reversed.
The effects of COPD are more intense. Cellular damage occurs in response to pathogens such as smoking or pollution. Excess mucus is secreted, and lungs suffer overall damage. Decreased lung function is irreversible, and combined with asthma, the decrease in lung function is accelerated. Lung damage interferes with oxygenation and pulmonary circulation, which strains the heart.
Both asthma and COPD can accompany the same coexisting conditions: cancer, depression, high blood pressure, impaired mobility, insomnia, migraines, sinusitis and stomach ulcers. However, 20 percent or more of COPD patients have a coexisting condition while people with asthma do not necessarily.
- Asthma Information - NIH.gov
- COPD Information - NIH.gov
- Prevention of Allergies and Asthma in Children - AAAAI
- Is it Asthma or COPD? - About.com
- Differential Assessment and Management of Asthma vs Chronic Obstructive Pulmonary Disease - The Medscape Journal of Medicine
- Calcium-sensing receptor antagonists abrogate airway hyperresponsiveness and inflammation in allergic asthma - Science Translational Medicine
- What Is a COPD Exacerbation? - About.com
- Chronic Obstructive Pulmonary Disease (COPD) and Asthma: Similarities and Differences - World Allergy Organization
- Asthma: Steps in testing and diagnosis - Mayo Clinic
- Smoking and COPD - CDC.gov
- COPD: Are You at Risk? (PDF) - National Heart, Lung, and Blood Institute