https://commons.wikimedia.org/wiki/File:Asthma_prevalence.pn... looks relatively steady over the last ~50 years or so.

> Asthma was recognized in ancient Egypt and was treated by drinking an incense mixture known as kyphi. It was officially named as a specific respiratory problem by Hippocrates circa 450 BC, with the Greek word for "panting" forming the basis of our modern name. In 200 BC, it was believed to be at least partly related to the emotions.

Theodore Roosevelt had asthma.