Everybody here on SB loves diving, and wants to be able to share this passion with everyone, including you....However....
"Asthma --- is to a scuba diver", what temporary blind spells ( coming out of no-where) -- are to "driving a car"....
Even mild asthma means that if your ascent rate takes off--an accidental BC inflation, you could die....where a diver with healthy lungs would only feel "embarrassed" .
There are some divers with mild asthma , and more than likely, they have rationalized it--if they do it, it must be smart....so they will be here soon enough, saying you should do what they did.
I don't think so.
I think I kinda of understand the connection you trying to make but I'm not sure on what rationale you are basing your opinion.
Obviously, if you have an asthma attack while diving that would be a bad thing. If you go blind while driving that also would be a bad thing. But, most drivers won't simply go blind while driving. However, asthma is technically a chronic condition that is characterized by periods of activity followed by periods of inactivity. In lay terms, that means you can go weeks to months without symptoms or needing medication to having the asthma triggered and then needing medication.
For starters, asthma is a disease characterized by a reversible constriction of the upper airways. That means that the muscles that control the upper airway go into spasm, the size of the airway itself decreases, and the patient then notes an increased work to breath. The characteristic sound is a wheeze when the patient tries to move air in and out of their lungs. It also means that the constriction is reversible, so that at some point it should reverse and go back to normal.
Typically speaking, there is a trigger that sets off a patient's asthma. It can be anything from an allergic reaction (like cats), to a cold, to environmental dust, and even dry air or cold. The last two are the problems for scuba diving. Scuba cylinders are filled with dry compressed air, and depending on ambient temperatures can be cold as well. For divers, a potential trigger just waiting to happen.
Asthma however has several different categories and subtypes. The actual medical assessment as to whether or not asthmatics can dive is debated amongst even the experts and no real consensus is agreed by expert doctors. For the most part, let's just say the the severity of the patient's asthma, how often they have exacertabations/attacks, and how easily and how much medication is required to get the asthma back under control is the guiding principle. The less severe the asthma, with very few exacerbations, and requires very little treatment that patient may very well try diving. The severe asthmatics, have frequent exacerbations, require multiple medications with high doses, that patient should not dive.
To the OP, you don't actually state how mild or severe your asthma is, how many or how often you take medications, if at all. I find that many patients report a history of childhood asthma but do not use any medications nor have any exacerbations as an adult. Many of these patients, however, still keep an inhaler handy just in case.
The only other test you may wish to do before you try diving is to have as asthma provocation test where the doctor does a pulmonary function test but tries to provoke an exacerbation of asthma during the test. Your GP can either do this test for you or refer to a pulmonary specialist and discuss the results. I'm not sure if you need an actual certified dive medicine MD to do this test either, any pulmonologist should be able to give an opinion on asthma as well and would at least be vaguely familiar with restricitons for scuba diving.
Good luck.
BTW - as to the assertion that a diver with asthma could die with accidental uncontrolled ascent that is not entirely true. The diver would have to have a very severe constriction coupled with a very fast ascent. The phenomenon is known as breath stacking and does not happen to asthmatics out in the public, but is usually seen in refractory asthmatics in the hospital (and generally not responding well to treatment either.) In breath stacking the patient has such a hard time exhaling air due to the asthma the actually have more air coming in with a breath than air going out with an exhalation. Again, this is very rare and is not clinically possible for an asthmatic patient diving. If the diver did not have an exacerbation and had a rapid ascent they would not be at any greater risk that a non-asthmatic. And, since the medical definition of "embarassment" implies compromise, a diver with embarrased breathing would likely have suffered some sort of trauma would still be at risk of dying later of complications.