Causes, symptoms and prevention of the invisible epidemic

At Aliantis, a holistic health clinic in Sitges, we believe caring for the body also means caring for the mind. Every day, we support individuals seeking balance, well-being and a more conscious relationship with their health. In the world of sport — where effort and achievement often go hand in hand — there is a silent threat that too often goes unnoticed: the sports-related concussion.

Known as the “invisible epidemic”, this brain injury can change an athlete’s life in a matter of seconds. It does not always cause loss of consciousness or visible signs, yet it can disturb memory, mood, concentration and overall brain health for weeks or even months.

In this article, we offer a comprehensive viewpoint on how to recognize, prevent and manage concussions in sports, promoting a culture of safety, respect and brain health to protect those we care about — our athletes.

A concussion is a temporary disruption of normal brain function caused by a direct or indirect blow to the head or body. Unlike other injuries, concussions often leave no visible signs, which makes them difficult to diagnose and treat appropriately.

The force of the impact can disturb neuronal functioning, leading to symptoms such as headache, dizziness, nausea, light sensitivity, confusion, or difficulty concentrating.

Recognising these early signals is essential to prevent longer-term neurological damage.

Concussions may occur in a wide range of sports and contexts — from collisions between players, falls, crashes, or repeated impacts.

Sports with particularly high risk include:

• Combat sports: boxing, taekwondo, MMA.
• Collision sports: American football, hockey, rugby, motor sports.
• High-fall risk sports: cycling, skiing, skateboarding, equestrian sports.

It is estimated that one in five contact-sport athletes suffers a concussion each season. Annual incidence rates range widely — from 200,000 to 3.8 million cases — in part because many incidents go unreported or unrecognized outside hospital settings.

A review of 25 studies on sports-related concussions indicates that female athletes are not only more likely to suffer a concussion, but also tend to endure more severe symptoms and longer recovery periods. In U.S. collegiate sports, for instance, women have been shown to be 1.9 times more likely than men to sustain a concussion in comparable disciplines.

Why this difference? Possible explanations include anatomical and hormonal factors: female athletes often have less cervical muscle mass, which may increase the movement of the brain inside the skull during impact. Hormonal fluctuations may also influence how the brain responds to trauma.

Real-life cases of well-known athletes illustrate how pervasive and unpredictable the risk is — regardless of their level or experience.

The Spanish basketball legend, with a distinguished career in the NBA and national team, suffered multiple concussions. In 2013, he was sidelined for 11 days after a hard elbow from JaVale McGee. The medical team of the Los Angeles Lakers even banned him from watching TV or using a computer to avoid overstimulation and support recovery.

During the 2012 UEFA Champions League semifinal between FC Barcelona and Chelsea, Piqué was hospitalized after a violent collision with his own goalkeeper Víctor Valdés while battling for a ball with Didier Drogba. He was substituted just 10 minutes later and diagnosed with a mild concussion — a case that reignited debate around safety protocols in European football.

The Mallorcan MotoGP rider sustained multiple concussions during his world-championship career. One of the most notable occurred during the 2016 Japanese Grand Prix practice, when a crash caused a mild traumatic brain injury. This incident highlighted the high risk faced by riders even during training sessions.

In 2023, Catalan cyclist Mireia Benito was forced to withdraw from the first stage of the Women’s Tour de France after a severe crash into a ditch, which resulted in a concussion. Her case became a stark reminder of the need for immediate medical evaluation — especially in women’s competition, where symptoms are often underestimated.

These examples show that no athlete — professional or amateur, male or female — is exempt from risk. They also illustrate that a proper medical approach can make the difference between full recovery and lasting damage.

Between 10% and 20% of individuals do not fully recover within the first few weeks and may develop a post-concussion syndrome (PCS). Symptoms can persist for months and include headache, dizziness, photophobia, fatigue, anxiety, insomnia, cognitive difficulties.

PCS can become chronic, severely affecting memory, concentration, emotional stability and quality of life. The burden on patients and healthcare systems is considerable.

One of the most serious, yet less-known early complications is the second-impact syndrome. This occurs when an athlete sustains a second head injury before fully recovering from the first. Even if the second hit is mild, the already inflamed and vulnerable brain may lose its capacity to regulate cerebral blood flow and intracranial pressure. This can trigger a rapid cerebral swelling (edema) that may cause a brain herniation.

Brain herniation refers to the displacement of brain tissue due to increased intracranial pressure, pushing parts of the brain through openings inside the skull. Such a shift can compress vital structures in the brainstem, impairing essential functions such as breathing or heartbeat. It is a medical emergency requiring immediate intervention — often surgical — and can be fatal.

The second-impact syndrome primarily affects adolescents and young adults, whose brain metabolism reacts differently post-trauma. Reported mortality rates reach 50%, and nearly all survivors suffer serious permanent neurological damage. The tragic death in 2021 of boxer Jeanette Zacarías Zapata, after sustaining two concussions within months, is a stark example of these catastrophic consequences.

Repeated brain injuries can also lead to long-term degenerative conditions such as Chronic Traumatic Encephalopathy (CTE) — characterised by symptoms like aggression, depression, paranoia, memory loss, confusion and dementia. Studies highlight the link between repeated head trauma and CTE, especially among professional athletes exposed over years to sub-concussive hits and concussions alike.

One extreme case is that of former American football player Phillip Adams, whose posthumous evaluation revealed advanced CTE after a professional career marked by repeated head injuries. His tragic death in 2021, involving the murder of five people and subsequent suicide, underscored global attention on brain trauma in high-contact sports.

At the first sign of a head injury, the priority must be safety and caution. The athlete should be immediately removed from play and evaluated by a qualified medical professional. If a professional is not available on site, coach or staff should be trained to recognise warning signs and to call for medical help promptly.

Key steps to follow when symptoms appear:

1. Assume a concussion may have occurred.
2. Withdraw the athlete from risk-exposure activities.
3. Do not allow return to play on the same day.
4. Monitor for worsening symptoms or red flags.
5. Seek urgent medical evaluation if symptoms escalate or persist.

Tools like SCAT5 (Sport Concussion Assessment Tool) are freely accessible and highly valuable for teams, physiotherapists and medical staff. Additionally, global sport organisations provide concussion protocols to follow after suspected head injuries.

While helmets and protective equipment can reduce some severe injuries (e.g. skull fractures), they do not guarantee prevention of concussions. Current studies show that no helmet — regardless of technology — can fully prevent the brain from moving inside the skull upon impact, which is often the mechanism behind concussions.

Moreover, protective gear can generate a sense of false security, leading to riskier behavior — a phenomenon often referred to as “risk compensation.”

Therefore, protective gear should be considered as part of a broader safety strategy, never as a standalone safeguard.

In recent years, growing concern over concussions has driven a quiet revolution in sports rules and protocols. International federations, professional leagues and medical organisations have gradually implemented stricter measures to protect athletes and ensure medical evaluation after any suspected head impact.

The National Football League (NFL) has banned head-first tackles and severely penalises hits targeting the opponent’s helmet. Players must undergo a mandatory medical assessment before returning to play, even if symptoms seem mild. These measures were introduced in response to evidence of long-term brain damage and degenerative conditions among former players.

World Rugby has adopted the Head Injury Assessment (HIA) protocol, allowing players to be temporarily removed for proper evaluation without penalising their team. In addition, stricter sanctions have been imposed for high tackles and head contacts, and coaching staff are encouraged to promote safer tackling techniques and respect for opponents.

In leagues such as the NHL, automatic video review systems penalise dangerous “checking” aimed at the head. Repeat offenders face suspensions, and referees are instructed to intervene at the slightest sign of reckless contact. These changes have notably reduced serious head injuries, although the high speed and physicality of the sport still represent a substantial risk.

European football has begun to adapt more slowly, but significant steps have been taken. Since 2021, top leagues like the Premier League and LaLiga have implemented concussion substitution rules — permitting a player suspected of head injury to be replaced without penalising the team. Referees are urged to stop play immediately when a potential head impact occurs, and national federations promote awareness campaigns about early recognition of symptoms.

Professional leagues such as the NBA have increased efforts to limit excessive physical contact, with stricter sanctions for dangerous moves, flagrant fouls and technical fouls when head impacts are at risk. Coaches are encouraged to teach safer defensive and blocking techniques, promoting a culture of respect and prevention on the court.

Beyond regulations and sanctions, these changes reflect a deep cultural shift: acknowledging that brain health must take precedence over short-term performance. Sports organisations are coming to understand that a protected athlete is not only safer — but also more resilient, balanced, and capable of a longer career.

Education and prevention remain the most powerful tools against this invisible epidemic. An athlete who has already suffered a concussion is five times more likely to experience another. After three events, the risk of developing a neurodegenerative disease increases significantly. Symptoms may appear up to 48 hours after the initial impact, and experts estimate that over 80% of concussions go undiagnosed.

Promoting a culture of brain safety, among athletes, coaches, families and clubs, is essential to ensure long-term well-being and sustainable sporting careers.

Sport is a source of energy, discipline and personal growth — but it must also be a space of respect for the body and the mind. Concussions are a reality that can no longer be ignored. Understanding their risks, applying proper protocols and fostering prevention does not weaken sport — quite the opposite. It makes it stronger, more humane and more sustainable.

At Aliantis, we advocate for a vision of sport that blends science with mindfulness. We support athletes not only in physical recovery but also in restoring inner balance, mental clarity and bodily awareness. Because when approached with respect and knowledge, sport becomes one of the greatest expressions of health and vitality.

Together, let’s work to make sport a safer and healthier environment for everyone.

This blog article is not intended to generate new knowledge; its content is based on a review of scientific publications, blog posts, and other written sources.