Asthma, whose name originates from the Greek meaning short of breath, is a chronic disorder of the lungs in which airways are inflamed and prone to constrict. This causes complications like wheezing, coughing, and breathlessness that range from mild to life- threatening. Approximately 10% of children and 5 % of adults worldwide suffer from some form of asthma.

Respiratory distress was first recorded in China in 2600 BCE, described as "noisy breathing," and treated with ephedra, a popularly known anti-asthmatic herbal medicine. Greek and Roman popular belief about asthma related it to demon possession, and Hippocrates recommended both ephedra and red wine as treatment. In 16th century Europe, tobacco was introduced for treatment of the condition, and although the root causes of asthma were becoming more known, the detrimental effects of smoking tobacco were not.
The first modern inhaler was invented because a 13 year old with asthma asked her father if it was possible for her medicine to come in a spray can "like they do hairspray." George L. Maison, the father in question, oversaw the development of the first metered-dose inhaler in just two months.

Today, sales of pharmaceutical inhalers globally exceed $36 million yearly, and more than 2000 people around the world use one per second. Breathing conditions aren't the only ones being considered for inhaler therapy- diabetics may one day find insulin available in inhalable form, and some inhalers deliver a peptide for treatment of osteoporosis.