The terms, reactive airways disease (RAD) and asthma, are often used interchangeably. Asthma is the more specific and inclusive term and reactive airways is a major feature of asthma, for almost all individuals with the disease. The term reactive airways describes a characteristic of one's airways, seen most commonly with asthma but also seen with chronic obstructive pulmonary disease (COPD), in which one's airways respond to infection, allergens or irritants with increased mucus and bronchial constriction at doses or concentrations that would have little or no effect on the airways of people with normally responsive airways. Thus, the other term used to describe reactive airways is that they are, hyperreactive, referred to as bronchial hyperreactivity.
Your concern about the most recent asthma exacerbation that led to an emergency room (ER) visit is warranted. Asthma severity and degree of control, characteristically varies over time, often over years. What happened this time suggests that you either had a more severe infection than usual or that your airways have become more responsive to infection. In either event, the response of you and your doctor should be to quickly regain control of your airways with prednisone, in addition to a program of regular medicine, to include an inhaled corticosteroid for no less than 3 to 6 months.
Keep in mind that acid reflux, also referred to as gastroesophageal reflux disease (GERD), is common, is a frequent cause of asthma worsening and often occurs at night. You should discuss with your doctor, if GERD might have been a factor, in this most recent episode.
This was scary but remember, asthma is a treatable, controllable disease and once it is controlled, you should be able to lead a normal life, without fear of awakening choking and short of breath, again.
Good luck.
I encourage you to see a pulmonogist for testing to more clearly define your disease and perhaps get you on some maintenance meds. Then you can also discuss when you need to go to the ER.
I raised two kids with asthma & have lung issues myself. At the recommendation of our Dr. we purchased a nebulizer--the machine they used in the ER to give you the breathing treatments. It delivers the same medicines available by inhaler, but more effectively. It has kept us out of the ER countless times.