Differences Between Asthma and COPD
Asthma and COPD are similar in many ways. They are also different in many ways. Here is a list of the differences between asthma and COPD.
Asthma vs COPD
- Years ago, asthma was an umbrella term under which all lung diseases fell, including COPD. Today, asthma is no longer considered an umbrella term.
- Today, asthma is a disease entity on its own. And, as a twist, COPD is now considered an umbrella term. The two most common diseases that fall under the umbrella of COPD are chronic bronchitis and emphysema.
- COPD is never asthma. But, sometimes asthma can become COPD.
Differences in symptoms
- Asthmatics only experience symptoms during asthma attacks. People living with COPD may experience some symptoms even on good COPD days.1
- When people living with asthma experience symptoms they are generally referred to as asthma attacks. When people living with COPD experience new or worsening symptoms they are generally referred to as COPD flare-ups.
- Asthma symptoms are completely or almost completely reversible with time or treatment. COPD symptoms are only partially reversible or not reversible at all.1
- Asthma symptoms only occur during asthma attacks. COPD symptoms may be present to some degree all the time.
Asthma vs COPD over time
- Asthma is usually considered a periodic disease. This means symptoms only occur sometimes. COPD is usually considered a persistent disease. This means that symptoms may appear to some degree all the time.
- Periods between asthma attacks may last days, weeks, months, or even years. In this way, asthma can seem to go into remission in some people. COPD flare-ups may also be periodic in this way. But, COPD does not go into remission.
- Asthma usually does not progress over time. COPD is generally considered a progressive disease. But, this progression may be slowed (sometimes significantly) with a proper diagnosis and aggressive treatment.
- Speaking of diagnosis, both diseases may be confirmed with a test called a pulmonary function test (PFT). The test will show if triggers cause airflow limitation. It can also show if this airflow limitation is reversible (indicating asthma) or not reversible (indicating COPD).
- Asthma medicines are used to prevent and control asthma symptoms. COPD medicines are used to allay symptoms and slow the progression of the disease.
Differences in inflammation
- There are two types of immune cells that cause airway inflammation: eosinophils and neutrophils. Both may be present in asthma and COPD. But, asthmatic inflammation is usually associated with eosinophils and COPD inflammation is usually associated with neutrophils.3,4
- Asthmatic inflammation responds well to corticosteroids and beta 2 adrenergic bronchodilators like albuterol (Ventolinn, ProAir). COPD inflammation responds less well to corticosteroids (although it may respond to some degree). It may respond to bronchodilators like albuterol. But, some studies show it responds better to muscarinic antagonist bronchodilators like ipratropium bromide (Atrovent) and tiotropium bromide (Spiriva).
- Asthma inflammation makes airways hypersensitive (twitchy) to asthma triggers. Exposure to triggers makes this inflammation worse. This is what causes asthma symptoms and asthma attacks. Hyperactive airways may cause some COPD flare-ups. But, there are various other components of COPD that may also cause flare-ups.3
Prevention and control
- Therefore, asthma can be prevented and controlled with a daily regimen of inhaled steroids and long-acting bronchodilators. Similar medicines can allay symptoms and slow the progression of COPD.
- Asthma attacks can be reversed using bronchodilators. Persistent attacks can be reversed with small doses of systemic corticosteroids. COPD flare-ups may be partially reversed with bronchodilators and systemic corticosteroids.
- They both respond to inhaler and nebulizer medications. These include bronchodilators and corticosteroids.
- Asthma generally does not require equipment other than inhalers and nebulizers. COPD may require other equipment, such as oxygen supplies, and machines such as CPAP and BiPAP.
- Asthma tends to be caused by asthma genes. So, it tends to be unpreventable. COPD is usually caused by long-term exposure to noxious substances that are inhaled. So, it is often considered a preventable disease.
- There are over 100 genes known to cause asthma. There is only one gene known to cause COPD. This gene may cause a rare form of COPD called alpha-1 antitrypsin deficiency. This is often referred to as genetic COPD.
- Therefore, most cases of asthma are said to be hereditary or genetic. At the present time, only 5% of people with COPD have genetic COPD. This means they develop it regardless of exposure to noxious substances in the air.2
- Asthma can be diagnosed at any time in a person’s life. COPD is usually not diagnosed until after the age of 40 or 45.
What to make of this?
So, there are many similarities between asthma and COPD. There are also many differences, as shown by this list.
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