What Football Does to the Brain, and What Families Need to Know

The hits that never made the highlight reel may be the ones that matter most. Decades of research have established that the cumulative effect of repetitive head trauma in football — including sub-concussive impacts that never produce a diagnosed concussion — can permanently alter brain structure and function. For former players now experiencing memory loss, mood changes, or cognitive decline, understanding the science is the first step toward understanding your legal options.

How Football Causes Chronic Brain Disease

Football brain injury is not a single event. It is the product of thousands of collisions — helmet-to-helmet, helmet-to-ground, shoulder-to-head — absorbed over years of practice and play. Each impact sets off a biochemical response inside the brain. When those responses compound without adequate recovery time, the damage accumulates at the cellular level in ways that may not become apparent for decades.

The medical community now recognizes that this pattern of repetitive head trauma can trigger the development of chronic traumatic encephalopathy, or CTE — a progressive neurodegenerative disease found in the brain tissue of former athletes at every level of the sport, from high school to the NFL.

What distinguishes CTE from a single traumatic brain injury is its latency. A player can absorb years of damaging head impacts, retire from the game, and appear entirely healthy for a decade or more before symptoms emerge. By the time a family recognizes something is wrong, the disease has often been progressing silently for years.

What Brain Injuries Do Football Players Get?

The research literature identifies several distinct conditions that appear at elevated rates among former football players. These are not theoretical risks — they are diagnoses documented in published neuropathological studies and confirmed in litigation.



• Chronic Traumatic Encephalopathy (CTE)
  A progressive neurodegenerative disease caused by repeated head trauma. Currently diagnosed only through post-mortem brain examination, though clinical diagnosis tools are advancing.
• Traumatic Encephalopathy Syndrome (TES)
  The clinical diagnosis applied to living patients whose symptom profile and history are consistent with underlying CTE pathology.
• Alzheimer's Disease
  Former NFL players have been found to develop Alzheimer's at significantly elevated rates compared to the general population.
• Amyotrophic Lateral Sclerosis (ALS)
  A fatal motor neuron disease documented at higher-than-expected rates among professional football players.
• Parkinson's Disease
  Linked in multiple studies to a history of repetitive head trauma.
• Depression, Anxiety, and Impulse Control Disorders
  Neuropsychiatric symptoms that frequently precede more severe cognitive decline and are increasingly understood as early CTE manifestations.
  

One of the most important — and least understood — findings in football brain injury research is that concussions alone do not explain the damage. Sub-concussive impacts, meaning head impacts that do not produce any recognized concussion symptoms, are now understood to be a primary driver of long-term neurological disease.

A lineman who played college football for four years absorbed an estimated 1,000 or more sub-concussive hits per season. Most of those hits were never recorded, never treated, and never reported. Under the NCAA's own protocols in effect through the 1990s and 2000s, they were not considered injuries at all.

The science has since caught up to what the game was doing to players. Biomechanical studies measuring head acceleration in live players, combined with post-mortem neuropathological findings, have established that sub-concussive impacts trigger the same tau protein accumulation associated with CTE — regardless of whether the player was ever diagnosed with a concussion.

This matters legally as much as it matters medically. The absence of a concussion diagnosis in a player's medical records does not mean the player's brain was not injured. It means the injury was never measured.

How CTE Is Diagnosed — and Why It Matters for Your Case

CTE can only be definitively confirmed through post-mortem examination of brain tissue. This is one of the most difficult realities families face: a living player cannot receive a confirmed CTE diagnosis, no matter how clear the symptoms appear.

What clinicians can do is apply the diagnosis of Traumatic Encephalopathy Syndrome to a living patient whose history — years of repetitive head trauma in football, combined with a characteristic symptom progression — is consistent with underlying CTE pathology. TES is not a workaround. It is an evidence-based clinical framework developed by leading neuropathologists to address exactly this diagnostic gap.

For litigation purposes, the distinction between a confirmed CTE diagnosis and a TES diagnosis matters less than the quality of the clinical and neuropathological evidence supporting the case. We have built cases — and won at trial — on the strength of documented symptom history, neuroimaging, neuropsychological testing, and expert testimony from the country's leading CTE researchers.

Second Impact Syndrome: When the Second Hit Is the One That Kills

Second impact syndrome occurs when a player sustains a second head impact before the brain has fully recovered from a prior injury. The result can be catastrophic and rapid — severe brain swelling, herniation, and death or permanent disability, sometimes within minutes of the second hit.

Unlike CTE, second impact syndrome is an acute event. It has claimed the lives of young players at the high school and college level, and it represents one of the clearest failures of return-to-play protocols — protocols the NCAA had a duty to establish and enforce.

For families who lost a player to second impact syndrome, or whose player sustained a catastrophic injury under these circumstances, the legal claims are distinct from latent CTE litigation but equally serious. Our page on second impact syndrome outlines what families in these situations need to know.

Frequently Asked Questions About NCAA Concussion Lawsuits