Concussion is a traumatic brain injury caused by a blow to the head or body that transmits force to the head. It alters mental status or causes other symptoms, but loss of consciousness does not always occur. In fact, a significant injury can occur without losing consciousness at all. Most concussions do not show up on routine imaging such as CT or MRI. Football players often say “I just got my bell rung” when a blow to the head causes ringing in the ears, but those symptoms are often consistent with concussion.
How is a concussion diagnosed?
When concussion is suspected, a certified athletic trainer or the team physician should immediately perform an initial “sideline” evaluation, including:
- Symptoms list review
- Focused neurological exam and balance assessment
- Focused orientation exam that tests short-term memory recall such as the event, play, opponent, score, or last meal
- Focused orientation exam that tests long-term recall such as name, birth date, place of birth
- Assessment of athlete’s ability to stay attentive to a complex task such as reciting months backwards
Team physicians and athletic trainers will use a test called the SCAT6 for children over the age of 13 and a CHILD SCAT6 for children age 8-12. The SCAT6 evaluation paired with the clinical judgement of the team physican or athletic trainer will determine whether a concussion has occured.
In some situations, athletes will complete a baseline assessment during their pre-participation physical, but this is not always required.
If left undiagnosed, a concussion may place an athlete at risk of developing second impact syndrome—a potentially fatal injury that occurs when an athlete sustains a second head injury before a previous head injury has completely healed.
Red Flag Symptoms Necessitating Immediate Medical Attention:
Worsening or Severe Headache
- Vomiting
- Seizure
- Weakness or Numbness
- Slurred Speech
- Worsening Confusion
- Unusual Behavior
- Asymmetric Pupils
- Neck Pain with Midline Tenderness
- Significant Drowsiness
What are the signs/symptoms of a concussion?
Concussion symptoms include the following:
- Balance problems
- Difficulty communicating, concentrating
- Dizziness
- Drowsiness
- Fatigue
- Feeling emotional
- Feeling mentally foggy
- Headache
- Irritability
- Memory difficulties
- Nausea
- Nervousness
- Numbness or tingling
- Sadness
- Sensitivity to light or noise
- Sleeping more than usual or difficulty falling asleep
- Visual problems—blurry or double vision
- Vomiting
- Pressure in head, neck pain, feeling slowed down
- Not feeling right
When is it safe to return to play?
All athletes who sustain a concussion should undergo an evaluation by a qualified healthcare provider before returning to play.
No athlete should return to sport during the same day as a suspected concussion.
Early management should consist of rest limiting physical and cognitive exertion and limiting screen time. Light activity such as walking can be re-introduced at 24-48 hours if the athlete is symptom free and approved by a team physician or athletic trainer.
Athletes can return to play after they have completed a 5-6 step “Return to Play” program and have started a “Return to Academics” program. Athletes must be completely free of all symptoms of a concussion and remain symptom free during and after physical testing to return to play. Most athletes can return to school with temporary support measures in place as early as 1-2 days.
What is baseline testing?
Unfortunately, it is difficult to determine if the brain has healed from a concussion; even after all symptoms have resolved, healing may not be complete. Neurocognitive testing can be a very helpful tool in determining brain function. With a comparison to a baseline test, this evaluation can be used in conjunction with a physician’s examination to reduce future risks.
Baseline testing collects data on an athlete’s cognitive and physical abilities prior to suffering the concussion. Baseline testing can include a neurocognitive evaluation (usually by computer) that tests multiple areas of brain function, including memory, problem solving, reaction times, and brain processing speeds. Symptom checklists, sideline assessment tools such as the Sideline Concussion Assessment Tool (SCAT-5), and balance testing are other examples of baseline evaluations that may be helpful.
Reviewed November 2025 by Elizabeth Dennis, MD
Contributing experts: Jeffrey S. Kutcher, MD; Wayne Sebastianelli, MD
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References
Patricios JS, Schneider KJ, Dvorak J, Ahmed OH, et. al. Consensus statement on concussion in sport: the 6th International Conference on Concussion in Sport-Amsterdam, October 2022. Br J Sports Med. 2023 Jun;57(11):695-711. doi: 10.1136/bjsports-2023-106898. PMID: 37316210.
International Conference on Concussion in Sport, Vienna, 2001; Prague, 2004; Zürich, 2008; Zürich, 2012, and Berlin, 2016, Amsterdam 2022