Asthma, a chronic medical condition, affects approximately 10 million Americans (3 to 4 percent of the population). Asthma results when triggers (or irritants) cause swelling of the tissues in the air passage of the lung, making it difficult to breathe. Typical symptoms of asthma include wheezing, shortness of breath, and coughing.
The above is some information I took off the web and is the conventional medical scientific explanation.
From a macrobiotic perspective the swelling of the mucus membranes of the lungs is a long term result of eating and drinking excessively yin foods and beverages. The main fooods implicated are any form of dairy food, any food or drink containing simple sugars like fruit, fruit juices, sweets/candy, refined flour products, and those foods containing chemicals like dyes, preservatives, etc. Also, too much liquid intake is a major factor.
An interesting observation here. A good friend and colleague, David Jackson, related at one Pacific Macrobiotic Conference (have you checked out the PMC Archives yet?) how he had observed since he started teaching and counseling in Arizona that many people relocate there because their asthma will tend to improve in the dry, desert climate. However, even though initially their asthma improves, because no-one has told them that excess liquid intake feeds the condition, within a couple of years their asthma is back worse than ever! In many cases, people get relief from their asthma when they start on their macrobiotic way of eating simply due to the less amount of liquid that is consumed.
The asthmatic attack is actually a response of the lungs to their overly yin condition in which the bronchiole muscles contract very sharply and it is this contraction that precipitates the asthmatic attack which is characterized by shortness of breath, wheezing, tightness in the chest etc. In other words, the asthmatic attack is the lungs attempt to balance its overly yin condition, with a sudden, sharp contraction (more yang).
So, although the actual asthmatic episode is a yang response, the underlying condition that gives rise to it is more yin. We also have to take into account the fact that the medications used to deal with the asthmatic attack are extremely yin, therefore the taking of them makes our condition more yin, basically feeding the condition.
In order to heal ourselves of this condition we change our way of eating to a macrobiotic way of eating, do the ginger compress regimen on the abdomen and the kidneys and start weaning ourselves off the medication. Since these medications are so powerful, I usually recommend that people keep taking their medication as needed for the first four months of eating macrobiotically before beginning to gradually wean themselves off them over a period of four to six months.