More than 300 million people worldwide currently live with asthma, making it one of the most common chronic diseases on the planet. In the United States alone, roughly 25 million people have a current asthma diagnosis, including about 4.7 million children.
Global Numbers at a Glance
The Global Initiative for Asthma (GINA) estimates that asthma affects over 300 million people across all age groups and regions. That number has climbed steadily from the 262 million estimated in 2019 by the World Health Organization. Globally, asthma kills about 1,000 people every day, totaling roughly 455,000 deaths per year. The vast majority of those deaths occur in low- and middle-income countries where access to inhalers and routine care is limited.
Asthma in the United States
CDC survey data from 2021 counted approximately 20.3 million adults (8.0% of the adult population) and 4.7 million children under 18 (6.5%) with current asthma. More recent 2024 figures show the adult rate has ticked up slightly to 8.6%, while the childhood rate has held steady at 6.5%. Combined, that puts the U.S. total near 25 million people, or about 1 in every 13 Americans.
Adults actually carry a higher prevalence rate than children, which surprises many people who think of asthma as primarily a childhood condition. While many kids do outgrow their symptoms, adult-onset asthma is common, and adults who had childhood asthma often see it return later in life.
Are Rates Going Up or Down?
The long-term trend is complicated. From 1990 through roughly 2018, global age-adjusted incidence and prevalence rates were gradually declining, dropping by about 1% to 2% per year. Better air quality standards, wider use of preventive inhalers, and public health campaigns all played a role.
That downward trend reversed between 2018 and 2021. During those years, global incidence rates rose by about 0.4% annually and prevalence climbed by about 0.3% per year. The shift was most pronounced in wealthier countries and among children under five, a pattern researchers have linked to the COVID-19 pandemic period. Respiratory infections, changes in healthcare access, and disrupted routines during lockdowns all likely contributed. Whether this uptick is temporary or the start of a longer reversal remains an open question.
Who Is Most Affected
Asthma does not affect all groups equally. In the United States, Black Americans have significantly higher rates of asthma, more emergency room visits, and higher death rates from the disease compared to white Americans. Hispanic and Puerto Rican populations also face disproportionately high rates. These gaps are driven less by genetics and more by environmental exposures: living near highways or industrial zones, older housing with mold or cockroach allergens, and unequal access to specialist care and preventive medications.
Income matters too. People living below the poverty line are more likely to have asthma and more likely to end up in the hospital because of it. When you can’t afford a daily controller inhaler or don’t have a regular doctor, mild asthma becomes severe asthma quickly.
The Economic Cost
Asthma is expensive at every level. In the United States, the disease cost an estimated $50.3 billion in direct medical expenses and another $29 billion in asthma-related mortality costs during the 2008 to 2013 period. Globally, the economic burden was projected at $1.4 trillion in 2023 and is expected to climb to $1.6 trillion by 2050.
What makes asthma particularly costly is how much of the burden comes from indirect expenses. A European study found that lost workdays and reduced daily activity accounted for 62.5% of the total cost per patient. In Asia, total societal costs per person ranged from $184 per year in Vietnam to nearly $1,200 in Hong Kong. In every region studied, uncontrolled asthma drove the highest costs. People whose symptoms are well managed with daily preventive treatment cost the healthcare system a fraction of what emergency-driven care costs.
Many Cases Go Undiagnosed
The 300 million figure is almost certainly an undercount. Asthma is widely underdiagnosed, particularly in low-income countries where spirometry testing (the breathing test used to confirm asthma) is not routinely available. Even in wealthy nations, mild or intermittent asthma often goes unrecognized. People chalk up their coughing, chest tightness, or shortness of breath during exercise to being “out of shape” or having seasonal allergies, and never receive a formal diagnosis. Studies in multiple countries have found that a substantial portion of people with asthma-like symptoms have never been told they have the condition.
This means the true global burden is likely well above 300 million. It also means that the death toll, concentrated in places with the least diagnostic infrastructure, reflects a disease that is almost entirely treatable when properly identified and managed.