By Ana Espino | Published on May 5, 2026 | 4 min read
Asthma is a chronic inflammatory disease of the airways
characterized by bronchial hyperresponsiveness, excessive mucus production, and
variable inflammation. It is not a single condition, but rather a group of
phenotypes based on different immunological mechanisms.
A major feature of asthma is the existence of marked sex
differences that evolve over the course of life. Asthma is more common in boys
during childhood, then becomes more prevalent and often more severe in women in
adulthood. These variations suggest a key role for sex hormones, as well as
genetic and immunological factors.
However, the precise mechanisms underlying these differences
remain incompletely understood. The data are heterogeneous, particularly
depending on life stages (childhood, pregnancy, menopause), and the
interactions between hormones, the immune system, and the environment are
complex.
In this context, this article, recently published in Immunological
Reviews, aims to better understand how sex hormones and chromosomal
differences influence the pathophysiology of asthma, in order to pave the way
for more personalized therapeutic strategies.
Why does asthma differ by sex?
Asthma involves multiple inflammatory mechanisms. Type 2
(Th2) inflammation leads to eosinophil infiltration, mucus production, and
bronchial hyperresponsiveness, while non–type 2 forms involve neutrophils and
Th1/Th17 responses.
Differences between men and women appear from childhood.
Boys have a higher incidence, notably due to anatomical factors (smaller
airways) and a more pronounced immune response. In contrast, in adulthood,
women experience more exacerbations and greater morbidity.
These variations are largely explained by the effects of sex
hormones:
- Androgens have a protective effect by reducing airway inflammation and
improving lung function
- Estrogens, via the ER-α receptor, promote certain inflammatory responses,
notably by increasing IL-33 production and activating Th2 and Th17 pathways
Hormonal fluctuations also play a key role. In women,
symptoms may vary during the menstrual cycle, worsen during pregnancy, or
change after menopause.
Other factors are involved, such as obesity, which increases
inflammation—particularly in women—and viral infections, whose impact differs
by sex. Finally, differences in gene expression linked to the X chromosome also
contribute to modulating the immune response.
Toward a differentiated approach?
Asthma is a complex disease whose expression varies
according to sex and life stage. This review highlights the central role of sex
hormones in modulating bronchial inflammation and disease severity.
Androgens appear overall protective, while estrogens may
amplify certain inflammatory responses, which could explain the greater
severity observed in adult women.
Beyond these observations, this work underscores the
importance of better taking into account sex differences in the understanding
and management of asthma.
“Understanding sex-related differences in asthma is
essential to adapt treatments and improve patient care,” the authors suggest.
It now remains to further explore the role of sex
chromosomes, better characterize hormonal effects across different stages of
life, and integrate these data into personalized therapeutic strategies at the
intersection of immunology, endocrinology, and precision medicine.
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About the author – Ana Espino
PhD in Immunology, specialized in Virology
As a scientific writer, Ana is passionate about bridging the gap
between research and real-world impact. With expertise in immunology, virology,
oncology, and clinical studies, she makes complex science clear and accessible.
Her mission: to accelerate knowledge sharing and empower evidence-based
decisions.
