Sports Brain Injuries, Concussions & CTE

What Happens to the Brain in Sports

Repeated hits to the head don’t just cause “one bad concussion.”
Over time, contact sports can create small but repeated injuries to the brain. Many are sub-concussive blows — hits that never get reported or recognized.

These repeated impacts can change how brain cells and networks work.
For some athletes, especially in high-impact sports, that damage can accumulate over years and lead to long-term problems, including chronic traumatic encephalopathy (CTE) and other forms of brain injury.

It’s Not Just Football

Football gets most of the attention, but the pattern shows up across many sports:

  • Hockey — checks into the boards, fights, falls

  • Boxing / MMA — repeated blows are the sport

  • Soccer — heading the ball, collisions in the air

  • Lacrosse — stick checks, accidental hits

  • Rugby — tackle impact without protective helmets

  • Cheer / gymnastics — falls from height

  • Cycling / skating — high-speed falls

Any activity involving fast movement + collisions + falls can create cumulative brain injuries.

Warning Signs Families Often Notice

These changes usually appear slowly:

  • Irritability or mood swings

  • Forgetfulness or misplacing items

  • Slower thinking or reaction time

  • Trouble planning or making decisions

  • Increased sensitivity to noise or stress

  • Headaches or “pressure” sensations

  • Trouble sleeping or waking unrefreshed

CTE cannot be diagnosed in life. These symptoms overlap with concussions, PTSD, depression, and neurological conditions, which is why evaluation matters.

What Doctors Look For

When athletes or veterans describe cognitive or emotional changes, clinicians often focus on:

  • Number and severity of prior head impacts

  • Time between injuries

  • Memory, attention, and executive-function changes

  • Sleep disruption

  • Behavioral changes (irritability, impulsivity, emotional flatness)

  • Other medical conditions that could interact with brain injury

How Families Can Prepare for Appointments

These steps make evaluations more accurate:

  • Write down when symptoms started and how they’ve changed

  • List any history of concussions, knock-outs, “seeing stars,” or big hits

  • Bring short examples of changes you’ve noticed

  • If possible, see a provider familiar with sports brain injury and CTE

We can’t diagnose or treat — but we can help you feel less alone and more prepared.

Learn More About Sports-Related Brain Injuries

Start here:

Last Updated: February 2026

Sources: CLF, NIH, peer-reviewed research summaries