Why Do Female Athletes Get More Concussions? The Evidence Explained.

Women report more concussions, experience worse symptoms, and take longer to recover than men in comparable sports. But is this simply over reporting or is something more fundamental going on?

The evidence increasingly says: both. And the distinction matters clinically.

Across football, rugby, basketball, lacrosse, and beyond, female athletes consistently show higher concussion rates than male counterparts playing the same sport. A growing body of research, spanning systematic reviews, meta-analyses, prospective cohort studies, and now neuroimaging and preclinical data, has set out to explain why. The answer is not a single mechanism. It is a convergence of biomechanical, structural, hormonal, cognitive, and social factors that interact in ways we are only beginning to unpick.

The Biomechanical Case: It Starts With the Neck

Perhaps the most consistently supported explanation in the literature concerns neck strength and head-neck dynamics.

Female athletes typically have less neck muscle mass and smaller neck girth relative to head size than males. This matters because the neck acts as a dynamic shock absorber: a stronger, better-conditioned neck can attenuate and redirect the forces generated at impact, reducing the accelerations that ultimately cause neural strain. Research suggests that every additional pound of neck strength is associated with roughly a 5% reduction in concussion odds in high school athletes (Fahr et al., 2024; Lin et al., 2018; Sundaram et al., 2022). It is a modest but meaningful effect, and critically, a modifiable one.

The nature of the impact itself also differs by sex. Female athletes are more likely to sustain concussions from ball, equipment, or surface contact, whereas male athletes are more commonly injured by direct player-to-player contact (Ling et al., 2020; Sundaram et al., 2022). These different impact vectors, often less anticipated and arriving from unexpected directions, reduce the opportunity for anticipatory neck bracing, amplifying the rotational accelerations that reach the brain.

Taken together, the biomechanical picture suggests that female athletes face a lower threshold for brain injury from equivalent impact magnitudes (McGroarty et al., 2020; Fahr et al., 2024). This is not a matter of fragility. It is physics applied to anatomy.

The Structural Picture: What Happens Inside the Brain

Biomechanics explains how forces reach the brain. A growing body of preclinical and neuroimaging research is beginning to explain why those same forces cause more damage once they do.

A 2024 study using a swine model, one of the most biomechanically comparable to humans, found that female brains contain a higher proportion of small-diameter axons in white matter compared to males. This is clinically significant. Smaller axons have less structural reserve and are more susceptible to the shear forces that characterise rapid acceleration-deceleration injury. Following a concussive impact, the female brains in this study showed more widespread axonal swelling and greater loss of sodium channels, proteins essential for neuronal signalling, even when the applied force was identical across sexes. Twenty-four hours after injury, the burden of axonal pathology was measurably greater in females.

This is a biological difference in tissue-level vulnerability, not a behavioural or reporting difference. And it has direct clinical implications: the disruption of sodium channel function impairs communication between brain regions, which may help explain why women consistently report more severe acute symptoms and longer recovery trajectories across observational studies.

Neuroimaging reviews add a further layer to this picture, identifying sex-based differences in white matter organisation, connectivity patterns, and regional vulnerability to shear strain (Macleod et al., 2025; Koerte et al., 2020). Together, these structural differences may influence how mechanical forces propagate through neural tissue during impact, meaning the same event that causes a mild concussion in one person may produce greater pathological change in another.

The Hormonal Question: Plausible, and Getting More Specific

Beyond structure, sex hormones, particularly oestradiol and progesterone, have attracted significant research attention as potential modulators of concussion risk and recovery.

Proposed mechanisms that may delay recovery include hormonal influences on cerebral blood flow, neuroinflammatory responses, and brain excitability. Some studies suggest that concussion may disrupt the hypothalamic-pituitary-ovarian (HPO) axis, with reports of menstrual irregularities following head injury and associations between cycle phase and symptom severity (McGroarty et al., 2020; Lin et al., 2018; Biegon, 2021). Elevated concussion rates have been observed in the luteal phase in some prospective cohort studies, adding temporal specificity to what had previously been treated as a static hormonal explanation.

For now, the hormonal contribution remains a credible and increasingly specific hypothesis, but one that still requires prospective studies with direct hormonal measurement to establish causation (Koerte et al., 2020; Macleod et al., 2025; Musko & Demetriades, 2023).

The Cognitive Dimension: A Piece of the Puzzle That Has Been Missing

One of the most overlooked contributors to injury risk in female athletes is cognition. Most research has focused on biomechanical mechanisms; far less has considered whether fluctuations in cognitive function across the menstrual cycle might independently modulate injury risk.

A UCL study by Ronca et al. (2024), published in Neuropsychologia, addressed this directly. Researchers tested 248 participants, including males, females on hormonal contraception, and naturally cycling females, on a sport-oriented cognitive battery measuring reaction times, sustained attention, inhibition, 3D spatial cognition, and crucially, spatial timing anticipation: the ability to predict when two objects moving at different speeds will collide, a process central to heading, tackling, and other time-critical sporting situations.

The within-subject findings in naturally cycling females were striking in two respects.

First, objective cognitive performance was best during menstruation, with faster reaction times, fewer errors, and less intra-individual variability, even though subjective mood and symptom burden were at their worst during the same phase. A significant proportion of women believed their symptoms were impairing their performance during menstruation. The data showed the opposite. This incongruence between perception and performance is clinically important: it suggests that the symptoms female athletes experience during menstruation do not reliably indicate that their cognitive function is impaired, and that assumptions to the contrary may be unfounded.

Second, and more concerning from an injury-risk perspective, performance on spatial timing anticipation was consistently and significantly worse during the luteal phase, regardless of test-retest learning effects. Reaction times were slower, timing errors were greater, and intra-individual variability was higher. The luteal phase is characterised by high progesterone, which has inhibitory effects on cortical excitability, potentially slowing the millisecond-accurate motor processes that underpin collision avoidance in fast-paced sport. This aligns with reports of elevated concussion and non-contact injury incidence during the luteal phase in other prospective studies.

Broader evidence on concentration across the cycle reinforces this picture. Peak cognitive performance, including better working memory, faster attention switching, and improved processing speed, tends to occur in the late follicular phase, when oestradiol is highest ahead of ovulation. The luteal and premenstrual phases are consistently associated with subjective concentration difficulties; some objective testing also demonstrates slower processing in these windows, and a 2025 longitudinal study found that sex differences in processing speed between men and women were most pronounced during menstruation specifically.

The critical clinical takeaway from this body of work is that neither cognitive performance nor injury risk tracks neatly with subjective symptom experience. Women may underperform cognitively in phases where they feel relatively well, and perform better in phases where they feel worse. This has direct implications for how clinicians, coaches, and sports scientists support female athletes across the training and competition cycle.

Reporting, Context, and the Social Layer

Any honest reading of this evidence must also grapple with reporting behaviour. Female athletes are generally more likely to disclose concussion symptoms than males (McGroarty et al., 2020; Merritt et al., 2019; Dick, 2009). This is well documented. More open reporting cultures, different social expectations around injury disclosure, and greater general health-seeking behaviour all contribute.

But, importantly, greater reporting does not fully account for the observed differences. Studies that have controlled for reporting behaviour still find higher symptom burden and longer recovery times in women (Covassin et al., 2017; Hannah et al., 2021). Women’s sports also typically involve less physical contact and lower-magnitude impacts than men’s equivalents, yet concussion rates remain elevated (Fahr et al., 2024; Dick, 2009). Higher disclosure partly explains the picture, but it does not complete it.

What the Research Does and Doesn’t Tell Us

The evidence is now strongest across multiple domains: neck strength and biomechanics as a modifiable risk factor; axonal microstructure and sodium channel vulnerability as a biological susceptibility; cognitive fluctuations across the menstrual cycle as a potential injury determinant that operates independently of symptom perception; and greater symptom burden in female athletes that persists even after controlling for reporting differences.

The hormonal literature, while increasingly specific, remains underpowered and awaits studies that directly measure hormone levels alongside injury and recovery outcomes. Many foundational studies rely on college-aged, predominantly white athletic populations, limiting generalisation (Brook et al., 2016; Macleod et al., 2025). The cognitive evidence, including Ronca et al. (2024), is proof-of-principle and needs replication in elite athletic populations with confirmed cycle tracking.

What the research tells us unambiguously is that the current evidence base was largely built on male athletes. Female-specific data across all these domains, structural, hormonal, and cognitive, remains sparse relative to the scale of female participation in sport.

What This Means in Practice

For clinicians working with female athletes, this evidence points to several practical priorities:

The Bigger Picture

The persistent assumption that concussion presents, progresses, and resolves in the same way regardless of sex is no longer defensible. It was never well evidenced. It simply reflected who the research was built around.

Female athletes are not men with different hormone levels. They present with different injury mechanics, different tissue-level vulnerability, cyclically fluctuating cognitive profiles that do not track with symptom perception, and, the evidence suggests, a genuinely different risk profile at every level from axon to sideline decision-making. Understanding all of that is not a niche concern for women’s sport specialists. It is a basic requirement of good concussion care.

The field is moving in the right direction. But the pace needs to match the scale of female participation in sport at every level, from grassroots to elite.