A Walk Through History: The 10 Root Causes of Asthma
Asthma has a long and rich history going all the way back to the beginning of time. It was described in the oldest known medical document, Nei Ching, written in 2,697B.C. by the Chinese Yellow Emperor, Huang Ti. Since then, most physicians based their remedies on what they suspected to be the root cause of asthma. Here are 10 past and present root causes of asthma.
1. Spirits. Primitive men and women believed your disease, your symptoms, were caused by powerful spirits lingering in the air around you. They might be a dead relative, or someone you killed in self defense. Or perhaps it’s a loved one who is punishing you for something horrible you did, or a bad thought you had. The treatment was a visit to the medicine man, an incantation, or amulet to ward off evil. While this may not have cured your asthma, it would have eased your mind by giving you hope and faith.
2. Angry gods. In the ancient worlds of Mesopotamia, China, Egypt, India, Greece, and Rome, your disease was caused by gods that were upset by something you did, said, or thought. The treatment was a visit to a temple of a god of health and healing, where the remedy was revealed to the priest while you were sleeping. While we may think of these primitive and ancient theories and remedies as quack medicine, it was very rational to people who lived back then. And, if nothing else, it gave asthmatics the hope and faith needed in a time where there truly were very few known remedies to help asthmatics breathe easier.
3. Phlegm. Hippocrates was the first physician to speculate that spirits, gods, and magic did not cause asthma, that it was caused by changes inside your body. He believed pneuma (air) was inhaled and flowed through veins to provide nutrients to the body. He believed phlegm was formed in the brain, and when in excess it flowed to the heart and lungs, causing epilepsy (spasms) of the airways. The treatment was a healthy diet and exercise. This theory, or some version of it, was popular among the medical profession all the way to the mid 19th century.
4. Nerves. Strong emotions, stress, and depression resulted in the brain sending impulses to the airways resulting in spasms and shortness of breath. This theory gained credibility in 1860 when Dr. Henry Hyde Salter published his book: “On Asthma: Its Pathology and Treatment.” The remedy was something to calm your nerves, such as a tobacco or Indian Hemp cigarette, a cup of coffee, strong tea, a whiff of ammonia, or a cup of brandy, whiskey, or gin. While these remedies may have helped to take the edge off of the feeling of air hunger, they did not relieve it. Despite this fact, this theory hung around for another 100 years.
5. Congestion. A common theory at the turn of the 19th century was that asthma was caused by dilated pulmonary blood vessels causing congestion of blood in the lungs. In 1901, epinephrine was discovered, and soon thereafter it was realized that it gave relief to asthmatics in a matter of 1-3 minutes. It was already known that epinephrine was a powerful vasoconstrictor useful for raising blood pressure. So, the theory was that it worked because it constricted pulmonary blood vessels to relieve congestion. This theory did not lead to any new asthma remedies simply by the fact it was based on a false premise.
6. Allergies. In 1901, two scientists discovered that proteins in the “Portuguese-man-of-war” caused anaphylaxis in dogs, and sometimes death. By 1906, other scientists linked these proteins to those in pollen, which was known to cause hay fever. Hay fever, now called allergies, was known to be a disease of a hyperactive immune response to allergens such as pollen. In 1910, another scientist recognized the similarities between allergies and asthma, and believed asthma was an allergic disease caused by allergens. A cure for allergies, therefore, would cure asthma. The excitement that ensued lead to the discovery of antihistamines, such as Benadryl.
7. Bronchospasm. Remember when Hippocrates speculated asthma was caused by airway spasms? This theory was proven in 1907 when Khan showed that epinephrine dilated airways, thereby allowing air to flow freely through them. This showed that the root cause of asthma was spasms of the smooth muscles wrapped around airways, causing them to constrict and narrow airways. This caused airway obstruction and asthma symptoms. The excitement that ensued ultimately lead to better asthma rescue medicine like albuterol and levalbuterol.
8. Inflammation. By the 1950s, corticosteroids were on the market, and physicians soon discovered it worked great for asthma. Yet side effects caused physicians to use this remedy only during life threatening asthma attacks. By the 1960s, inhaled corticosteroids were found to be safe and effective for controlling asthma, and by the 1980s they were readily used as asthma controller medicines. By 1989, it was discovered that they worked by reducing inflammation, leading to the discovery that the root cause of asthma was chronic (it’s always there) underlying airway inflammation making airways hypersensitive to asthma triggers.
9. Genes. Also in 1989, the first asthma gene was discovered. Since then over 100 have been discovered. Genetic research has shown researchers that asthma is a single disease with many root causes, not just one cause. This is because every asthmatic has a unique combination of asthma genes, and each of these genes plays a unique role in the development of asthma. What combination of genes you have determines when you will develop it, what subtype of asthma you will develop, how severe it will be, and what medicines will work.
10. Unknown. So what is the root cause of asthma? Quite honestly, despite how far we have come, researchers still do not know. In fact, the more researchers learn, the more complex they realize this disease is, making it quite understandable how the true root cause(s) of our disease has/have eluded medical experts since the beginning of time.