Why is there a rise in Asthma?
Quick Answer
Asthma prevalence has roughly doubled in many countries over the past 40–50 years, and researchers agree the increase is too fast to be genetic. Mainstream medicine attributes it to a combination of factors: the "hygiene hypothesis" (reduced early-life microbial exposure), urbanisation and air pollution, indoor allergens from modern, tightly-insulated housing, tobacco smoke exposure, and antibiotic overuse. Breathing pattern, specifically chronic overbreathing, is a separate, more contested theory (associated with the Buteyko method) about what worsens symptoms once asthma is present, not the established explanation for why global rates are rising. Both are covered below, clearly separated.
Asthma is increasing worldwide, affecting children and adults across both urban and rural environments. Childhood asthma prevalence alone has increased by roughly 12.6% over the past 30 years, with more than 262 million people currently affected globally. Genetics play a role in individual risk, but as researchers studying the trend point out, the speed of this rise argues strongly against a purely genetic explanation, something in the environment or in how we live has shifted.
It's worth being precise about what "the rise in asthma" actually refers to here, because two different questions get conflated a lot in wellness content: why has population-level prevalence gone up, and what makes an individual's asthma symptoms worse day to day. Mainstream research answers the first question fairly consistently. The second question is where breathing pattern, and more specifically the Buteyko method's "overbreathing" theory becomes relevant, but it's one contributing factor among several, not the root cause of the epidemic.
What Mainstream Research Attributes the Rise To
Researchers describe the growing asthma epidemic as complex and multifactorial, but a few drivers show up consistently across the literature:
The hygiene hypothesis. First proposed by Strachan in 1989, this theory holds that reduced exposure to naturally occurring microbes in early life may prevent the immune system from maturing in a way that would otherwise protect against allergic disease and asthma. Living in an urbanised environment and exposure to pollution are established risk factors, while larger family size and early microbial exposure. For instance from farm animals, appear protective. It's worth noting this hypothesis is still debated: some developed countries have seen asthma decline without any corresponding change in hygiene standards, which the hygiene hypothesis alone doesn't explain.
Urbanisation and early-life exposures. The World Health Organization notes that urbanisation is linked to increased asthma prevalence, likely through multiple lifestyle factors, and that early-life events including low birth weight, prematurity, tobacco smoke exposure, air pollution, and viral respiratory infections raise later asthma risk.
Indoor allergens and modern housing. Tighter insulation, carpeting, and modern furnishings increase exposure to house dust mites, mould, and pet allergens indoors, a shift that tracks with rising rates in industrialised countries.
Air pollution and climate change. Some researchers propose that rising atmospheric CO2 and global temperatures are increasing pollen quantity, extending pollen seasons, and increasing pollen allergenicity, potentially compounding asthma and related allergic conditions. Air quality's role is real but not simple: a recent cross-country analysis found the relationship between air quality and asthma prevalence wasn't consistent, since some countries with poor air quality had lower reported asthma rates than countries with good air quality. A reminder that this is a genuinely multifactorial picture, not a single-cause story.
Antibiotic use and childhood infections. Childhood antibiotic use has also been linked to higher asthma risk, alongside the broader pattern of reduced microbial exposure in early life. None of this is settled science with one clean answer, researchers actively debate how much weight each factor carries, and that debate is part of why this is a genuinely hard question rather than a marketing opportunity for any single intervention, breathwork included.
None of this is settled science with one clean answer. Researchers actively debate how much weight each factor carries, and that debate is part of why this is a genuinely hard question rather than a marketing opportunity for any single intervention, breathwork included.
Airway Sensitivity: What's Actually Happening in the Body
Asthma is characterised by inflammation and narrowing of the airways. Once that sensitivity is established, the airway reacts strongly to triggers; allergens, pollution, cold air, stress, infection that produce the familiar symptoms: shortness of breath, wheezing, chest tightness, and coughing, especially at night. Asthma isn't purely a lung condition. It involves the respiratory system, the immune system, and the nervous system together which is part of why stress and nervous-system state can influence symptom severity even though they're not the underlying cause of the disease.
Where Breathing Pattern Fits: The Overbreathing Theory
This is where breathwork's contribution actually sits, and it's important to be precise about its status: the "overbreathing" or Buteyko theory is one framework for understanding symptom severity, not a mainstream-consensus explanation for rising asthma prevalence. It has real proponents and some supportive research, and it's also genuinely contested within respiratory medicine. Treat what follows as one lens, not the final word.
The theory proposes that several features of modern life encourage chronic overbreathing (breathing more air than the body needs), which can worsen or trigger asthma symptoms in people who already have airway sensitivity:
Diet - Overeating and highly processed, acid-forming foods are theorised to increase breathing volume as the body works to buffer blood pH by exhaling more CO2.
Talking - Extended speaking requires frequent large inhales; people in speech-heavy jobs (retail, call centres, teaching) often report feeling depleted and constricted by day's end.
Stress - The fight-or-flight response increases breathing rate in preparation for physical exertion that, in modern stressors, rarely happens — so the physiological "discharge" the body prepared for never occurs.
Sedentary lifestyle - Muscle activity generates CO2; a large drop in daily physical activity over the past decades corresponds with lower CO2 production and, per this theory, larger resting breathing volume.
"Big" breathing habits - A widespread but, per Buteyko practitioners, mistaken belief that big, visible chest breaths are healthier than gentle, diaphragmatic ones. They argue this encourages chronic overbreathing.
Reactions to asthma itself - Airway constriction can trigger panic-driven overbreathing, which this theory holds worsens constriction further — a feedback loop it argues can only be interrupted with either medication or breath retraining.
Overheated, under-ventilated buildings - Poor temperature regulation in modern insulated buildings is theorised to push the body toward heavier breathing as a cooling mechanism.
The CO2 mechanism this theory relies on
CO2 is produced as the body metabolises food and is carried by the blood to the lungs for exhalation.
Normal physiological function requires a baseline level of CO2 in the blood, not just oxygen.
Via the Bohr effect - a well-established, textbook physiological principle discovered in 1904, describing how CO2 levels affect haemoglobin's release of oxygen to tissue, overbreathing theory holds that chronically low CO2 can impair oxygen delivery even when blood oxygen saturation looks normal.
Healthy blood oxygen saturation sits around 95–98%, and even during intense exercise the body typically exhales a substantial share of the oxygen it takes in - meaning breathing a larger volume of air doesn't straightforwardly increase oxygen delivery, per this framework.
Where this theory is more and less accepted: the Bohr effect itself is uncontroversial physiology. What's contested is how much weight chronic mild hypocapnia carries as a driver of asthma symptom severity specifically, versus the inflammatory and allergic mechanisms that mainstream pulmonology treats as primary. Buteyko-based breathing retraining has some clinical trial support as a symptom-management tool, but it is not positioned by respiratory medicine as addressing the underlying inflammatory disease process.
Breathwork and Airway Support: What It Can and Can't Do
Breathwork can support nervous system regulation and reduce chronic overbreathing patterns, which may in turn reduce respiratory strain and improve day-to-day symptom experience for some people. Slow, nasal breathing practices are associated with improved breathing efficiency and reduced overbreathing.
What breathwork does not do: treat the underlying airway inflammation that defines asthma, replace prescribed medication (including rescue inhalers and controller medications), or reverse the environmental and immunological drivers covered above. If you have diagnosed asthma, breath retraining is worth exploring as a complementary practice alongside medical care and in conversation with your doctor — not as a substitute for either.
Further Reading
Sources referenced
WHO — Asthma fact sheet: https://www.who.int/news-room/fact-sheets/detail/asthma
Strachan's hygiene hypothesis, original and follow-up literature:
Hygiene hypothesis and global asthma incidence, contested evidence:
https://www.taylorfrancis.com/chapters/edit/10.1201/9781003125785-12
Epidemiology of Asthma in Children and Adults:
Global rise of asthma and climate change:
Air quality vs. asthma prevalence, cross-country analysis:
Temporal trends in childhood asthma, Global Burden of Disease data:
