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Monday, January 10, 2011

Asthma: More than just a lung disease

When asthma was first described in ancient writings it was all about being short of breath, which is basically the Greek definition of Asthma (panting). Yet our new definition describes asthma as more than just a disease of the lungs.

I expound on this idea in a recent post from

Evolution of Asthma: More than just a lung disease

Asthma has traditionally been considered a disorder of the lungs. This makes sense since a tell-tale sign of this disease is difficulty with breathing. Yet the evolution of the term might soon include more than just the lungs.

In a sense, as more evidence has come to fruition over the 5,000 year history of asthma, the definition has evolved. The word asthma was first used by the ancient Greeks, as "asthmae," which means short, gasping breaths.

Basically, even into the early 20th century, all that caused shortness of breath was referred to as asthma, including bronchitis, emphysema, pneumonia and heart failure.

Yet eventually those diseases earned their own categories, and the asthma definition evolved into what we know it as today.

By 1959 asthma was defined as a disease where the air passages (bronchioles) of your lungs become narrow (bronchospasm) and this is reversible either spontaneously or with medicine.

By 1962 asthma was defined as a disease whereby the bronchioles become hyperresponsive and narrow as a result of exposure to various stimuli (asthma triggers).

By 1987 the key component was defined as airway obstruction caused when the lungs are exposed to asthma triggers. This obstruction consists of airway narrowing caused by bronchial muscle spasms (bronchospasm), increased mucus production, and swelling of the cells surrounding the lungs (inflammation).

By 2000, the term evolved to include two key components.

  • Chronic inflammation: Swelling of the airways that is always there. The severity of asthma is determined by the degree of swelling. Likewise, this swelling can be controlled with asthma controller medicines.

  • Acute Bronchospasm: Exposure to asthma triggers can make this inflammation worse, thus causing airway narrowing. This can be reversed with time or with medicine. Likewise, in many cases, this can be prevented with medicines, control of inflammation, and avoidance of asthma triggers.

That's where we stand today, although with studies ongoing, and scientists now studying the newly found asthma genes, it's possible this definition will continue its evolution.

Another thing that might further evolve the definition of asthma is the fact this disease has been linked to various other systems of the body, kind of like the way cystic fibrosis effects not just the lungs but the kidneys too.

Thus, in reality, asthma may be more than just a lung disease. The following is a list of systems currently believed to be linked with asthma:

1. Lungs : Well, we already knew this. It causes difficulty breathing.

2. Autoimmune system: For an unknown reason (however there are theories), the immune systems of people with asthma recognize harmless substances such as dust mites, molds, animal dander, and cockroach urine as harmful, and attacks these as though they were harmful substances like viruses and bacteria. This results in the so called asthma and allergy attacks. It has been proven that 75 percent of asthmatics have allergies. So you'll see many asthmatics on allergy meds such as antihistamines, decongestants, and leukotriene blockers.

3. Stomach: Even in old texts, asthma was linked to the stomach. Experts realized long ago that eating too much, especially before bed, often triggered asthma. We now know that Gastro Intestinal Reflux Disease (GERD) can not only cause asthma, but it can trigger it too (Read more here). This is why you'll see many asthmatics on anti-reflux medicine. A bloated stomach can also push up on the diaghragm, which makes less room for the lungs to expand. For this reason, a good diet is also important for asthmatics.

4. Psychological: Studies show that asthma is not caused by anxiety and depression as asthma doctors in the 19th century believed. But those things can trigger an asthma attack. Yet, even further, studies have found a link between anxiety and depression and asthma, as you can read by this great article.

5. Sleep: Since asthma often occurs in the night it often causes trouble sleeping. In fact, as you can read here, studies have noted that as many as 50 percent to 75 percent of asthmatics have noted trouble sleeping, even if their asthma is controlled. Even many old asthma texts often mention insomnia as a common occurrence among asthmatics.

6. Skin: Long ago asthma experts noticed a link between asthma and skin disorders. Atopic dermatitis, or eczema, was one of them. Psoriasis is another. In fact, many children diagnosed with excema are later diagnosed with asthma (as you can read here). It's interesting to learn that now scientists believe the gene that causes these skin disorders and the gene that causes asthma are one and the same (as you can read here).

7. Nose: Many asthmatics through the course of recorded history have been reported to have also be prone to infections called sinusitis and nasal inflammation called rhinitis, or more commonly referred to as hay fever. Untreated, these conditions can lead to nasa polyps, crooked septums and, yes, even asthma.

Likewise, as you can read here, sinusitus and rhinitis are "comorbidities" that often go hand in hand. In fact, studies show that while 75 percent of asthmatics have allergies, about 50 percent of these allergic asthmatics also suffer from bouts of sinusitis. Treatment and control of these nasal problems usually allows for better asthma control.

8. Eyes: Child asthmatics with allergic asthma are prone to conjunctivitis. Likewise, allergies can often cause the eyes to become dry, red and itchy.

9. Nutrition/Exercise: Recent studies have linked being overweight with worsening asthma (read more here). Fat around the lungs can actually squeeze the lungs giving them less room to expand, which is the same as what occurs when the stomach is full or bloated. Likewise, studies also show obesity makes asthma medicines work less well.

It should also be noted here that exercise has been linked to improved lung and heart function, and also improves the immune system. A good diet, along with weight loss if necessary, has been linked to better asthma control. To learn more check out this sharepost.

10. Exercise Induced Bronchospasm (EIB): Studies have proven that up to 90 percent of asthmatics have exercise induced asthma (EIA). Of course many believe EIA is inappropriately named too, that it should be termed EIB, which is what I use. I wrote about EIB here.

A poll in one of my respiratory therapy magazines asks if the name asthma should be changed, and the result was a resounding no. So I wouldn't expect the name "Asthma" to change in the future. Yet the definition is most likely certain to change as new asthma wisdom is learned.

As one of my fellow asthma experts writes in this sharepost, "Asthma is not just one disorder, but a syndrome." It's more than just a lung disease.



Pissed Off Patient said...

I keep waiting for science to recognize that the inflammation of asthma is not confined to the lungs, but is systemic. I seem to have lots of inflammation issues.


Rick Frea said...

Great point.

Dr. Renee said...

I am a fellow asthmatic please check out my blog