As many primary care physicians and pulmonologists know all too well, the winter months can be challenging for many of the near 26 million people living with asthma in the US.

Whether inside or outside, this time of year presents triggers for asthmatics—from cold air and dry wind, to respiratory viruses, to dust circulating in heating systems, to smoke from wood-burning fires and more—increasing their risk of asthma attacks.

This season can be especially difficult for approximately 2.6 million Americans living with severe asthma, as their attacks can potentially be serious and frequent. But what many people may not know is that if not adequately managed, severe asthma can be debilitating, negatively impacting patients’ lives at home, work, or school, with some asthma attacks that can even be fatal. Even when the season passes, some severe asthma patients may still find themselves suffering from the same symptoms, and many may even be left wondering the cause of their asthma in the first place.

This may be attributed to the decades-old belief by many asthma patients and providers that there is only one type of asthma. However, we’re now recognizing that asthma is a heterogeneous disease—there’s not just one type of inflammation driving this disease