Asthma is a chronic lung disease characterized by inflammation and narrowing of the airways.^[1] Individuals with asthma experience recurrent episodes of wheezing, breathlessness, chest tightness, and coughing.^[2] These episodes are often worse in the mornings and evenings.

Asthma is diagnosed through a combination of clinical and laboratory tools. Typically, a diagnosis is formed from a combination of patient history, a physical examination of the lungs (using a stethoscope), and lung function tests (e.g., spirometry, peak expiratory flow, and response to an inhaler).^[4] Additionally, since allergens can provoke immune responses that worsen the symptoms of asthma, clinicians may also do allergy tests.

Inhalers are the primary medical treatment for asthma. During acute exacerbations, inhaled short-acting beta-agonists (SABAs), such as albuterol/salbutamol, are considered the primary tool for managing asthma.^[5] As their name suggests, these drugs bind to β₂ adrenergic receptors and cause the smooth muscles in the bronchi to relax and open.^[6][5] Additionally, if asthma is classified as “intermittent” or worse, inhaled long-acting beta-agonists (LABAs) and glucocorticoids can be used for more continuous treatment.^[7]

A handful of supplements have been studied for asthma, but none exhaustively so. Magnesium, Coleus forskohlii, pycnogenol, and saffron all have a few studies suggesting they modestly improve asthma symptoms.

There are several noteworthy connections between diet and asthma. Consumption of fruits, vegetables, and dairy have all been correlated with a reduced risk of Asthma.^[8] Additionally, switching from a proinflammatory diet (such as the Western diet) to a less inflammatory diet (such as the Mediterranean diet) may reduce the risk of asthma.^[9] Finally, there is evidence that alterations to the microbiome (e.g., by antibiotic use early in life) may increase the risk of asthma later in life.^[10]

Alongside inhalers, avoiding triggers is a major part of asthma treatment. Ideally, individuals with asthma should keep track of environments, activities, and substances that make their asthma worse and avoid them (or at least bring and use an inhaler).

The cause of asthma is unclear; it’s a combination of genetics and environment.^[1] Acute episodes of asthma can be caused by exposure to allergens (e.g., dust mites, mold, pollen), exposure to nonallergens (e.g., cold air, household chemicals, smoke/pollution), or exercise.