Our immune system is supposed to fight germs, but in some people, it gets triggered by harmless substances in the air (pollen, molds, microscopic particles from animals (esp. cockroaches), dust mites). If the lungs are involved, they get Asthma. Asthma can also be triggered by cigarette smoke, viruses, cold food, even by exercise (athletes are allowed to use drugs for asthma without any penalty).
In the lungs, the bronchi are affected (see Diagram — Lower Respiratory Tract). Irritated bronchial muscles tighten up (“bronchoconstriction”). The mucous membrane lining of the bronchi swell, and make mucus. All this narrows the airway passages, causing shortness of breath, cough, or both.
The course of Asthma is different for almost everyone. Some people mainly cough, others mainly have shortness of breath. Some have attacks on & off, others have it continuously. Some people have mild asthma, others severe. One attack can be mild, and the next one severe. The disease may seem to go away, but recur years later. Although there are deaths from asthma, that’s pretty rare. Overall, people with asthma have a fairly normal lifespan. People most at risk of dying from asthma are those who’ve been admitted to the hospital for it in the last year, those who’ve made frequent ER visits in the past few months, anyone who’s ever been in an ICU for asthma, and asthmatics who also have severe mental illness (mainly psychotic disorders).
We easily diagnose asthma by hearing wheezes in the lungs, with a stethoscope. Wheezes are not just any rattling sound; they’re long, high-pitched, and occur during expiration (breathing out). However, some patients don’t have classic wheezing, but lots of squeaks & gurgles during either inspiration and/or expiration, called “rhonchi.” Unfortunately, a number of clinicians say “asthma” for wheezes, and “bronchitis” if there are any rhonchi. Then they give antibiotics for the latter. So not only do they create risk of drug resistance from antibiotic overuse (i.e. misuse), they don’t even prescribe what the patient really needs — asthma medications.
And some patients seem to have clear lungs, but if we listen clearly with our stethoscope, we hear that expiration lasts longer than inspiration. This is the opposite of normal lungs, & is as good a finding for asthma as wheezes are. If a clinician ever tells you, “your lungs are clear,” ask if inspiration is longer than expiration (normal), or vise versa (abnormal). [Note — when simply watching a person breathe normally, expiration seems long than inspiration, but by stethoscope inspiration sounds longer].
Some patients have what we informally call “cough asthma,” meaning their lungs sound completely normal in all respects, but the cough is still asthma. We can diagnose this by ordering pulmonary function tests. But usually, we just treat for Asthma. If the cough gets better, we stop treatment. If it comes back, we resume it, & are pretty certain of our diagnosis.
Asthma that’s triggered by exercise is called “exercise-induced asthma.” We suspect it by history, since at rest (sitting on an exam table) the lungs sound fine, & all tests are normal at rest. So I try asthma treatment, maybe telling them to use an albuterol inhaler 30 minutes before they exercise. If that prevents symptoms, we have a diagnosis.
The very first asthma attack is impossible to distinguish from Acute Bronchitis (caused by a virus). Even after the virus dies off, symptoms can last a few months. Even if I treat with asthma medications, I tell patients that we can’t say “Asthma” until symptoms clear up, & then recur in the future.
The opposite is also true, as noted above. I’ve seen patients diagnosed with “bronchitis” over & over again, & often given antibiotics (which are useless in acute bronchitis). Viral bronchitis doesn’t keep coming back; such patients need solid treatment for Asthma.
For patients with a chronic cough lasting over a month, and a normal chest x-ray, 99% will have one of the following conditions:
- Allergic Rhinitis (hay fever)
- Esophageal Reflux (heartburn)
- Asthma (Chronic Bronchitis if a smoker)
There are various types of medications for asthma, that have few side effects if any. Nobody with asthma should have to suffer ongoing symptoms.