The Complete Concussions Knowledge Base

Every answer on
concussion & recovery, in one place.

Research-backed articles, clinical protocols and plain-English explainers, all reviewed by Complete Concussions certified clinicians. Find answers to any and all of your concussion and brain health questions.

248
Evidence-backed articles
10
Topic categories
Weekly
New research breakdowns
The Topics
01 / 10

Symptoms & What To Do Next

Plain-language triage for anyone who just took a hit or watched someone else take one. What counts as a concussion, which red flags mean the ER, and what the first 48 hours should actually look like.

15 Early Concussion Symptoms You Should Never Ignore

If you or a family member just experienced a hit to the head or body, it can be hard to know what is normal and what is dangerous. This guide

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TLDR: How do I Know if I Have a Concussion

You’ve just taken a hit — maybe during a game, in a car accident, or even from a fall. Your head’s rattled, you’re feeling off, and you’re wondering: “Do I

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TLDR: Can you get a Concussion From Whiplash?

Introduction: Concussion Without a Head Hit? Most people associate concussion with a direct blow to the head. But did you know that you can sustain a concussion even without any

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Frequently asked
Quick Answers
Common concussion symptoms include headache, dizziness, nausea, light or noise sensitivity, brain fog, fatigue, sleep changes, mood changes, and trouble concentrating. Symptoms can look different from person to person and may change during recovery.
Stop the activity, monitor symptoms, avoid another hit, and get assessed by a healthcare provider. If symptoms worsen or danger signs appear, seek urgent medical care. Early guidance can help create a safer recovery plan.
Go to the ER or call emergency services if there is worsening headache, repeated vomiting, seizure, increasing confusion, weakness, slurred speech, unequal pupils, severe drowsiness, or loss of consciousness with trouble waking.
Yes. Most concussions do not require a loss of consciousness. A concussion can happen after a blow to the head, face, neck, or body that causes rapid movement of the brain.
Yes. Concussion symptoms may appear right away, but they can also develop hours or days later. That is why monitoring after a head injury is important, especially if symptoms change or worsen.
For patients & families
Found a symptom that worries you? Talk to a certified clinician.

Every provider in our directory has completed our full evidence-based training and uses the protocols in this topic. Search by your location. 

02 / 10

Diagnosis, Testing & Imaging

SCAT6, DANA, QEEG, MRI, fluid biomarkers, what each tool tells you, and what it cannot. A clinician-first view that carries for curious patients too.

Concussion Diagnosis: Can Blood Tests Help?

Blood tests are used to detect everything from infections to cardiac injury — but what about concussions? Over the past decade, researchers have been exploring blood-based biomarkers to help diagnose

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TLDR: How to Conduct a Cranial Nerve Exam

Cranial nerve exams are a vital part of the neurological screen following head trauma. While concussions are considered functional injuries (with no structural damage on imaging), signs of cranial nerve

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Quick Look: What is the SCAT6 Concussion Test?

Introduction: The Need for a Reliable Concussion Test When someone sustains a potential concussion, having a quick and reliable evaluation method is crucial. That’s where the SCAT6 comes in. The

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Frequently asked
Quick Answers
A concussion is diagnosed clinically, based on the injury, symptoms, medical history, and physical exam. Testing may include balance, vision, reaction time, memory, symptom scales, and neurological screening.

A normal CT or MRI is common after concussion because these scans look for structural injuries, not all changes in brain function. You can still have real, manageable symptoms even when routine imaging is normal.

Not everyone with a concussion needs imaging. CT or MRI is usually considered when there are red flags, concern for bleeding or fracture, worsening symptoms, or another diagnosis that needs to be ruled out.

Blood biomarkers may help guide some acute CT decisions in certain settings, but they do not replace a clinical concussion assessment. Diagnosis still depends on the injury history, symptoms, exam findings, and clinical judgment.

Common concussion tests may assess symptoms, balance, eye movement, reaction time, memory, cognition, neck function, and exercise tolerance. No single test tells the whole story, so a comprehensive assessment is preferred.

03 / 10

Baseline Testing

How baseline cognitive, vestibular and balance testing actually works, and why data without the right protocol is worse than no data at all. For athletes, teams, and an emerging use-case in senior care.

TLDR: A Quick Guide to Concussion Baseline Testing

Baseline testing is one of the most effective tools we have to ensure safe concussion recovery and return-to-play decisions. Yet, it’s also one of the most misunderstood. Many assume that

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Complete Concussions | Baseline Testing Protocol & Supporting Evidence.

Purpose Resolution of symptoms following concussion is a poor indicator of brain recovery (1). Concussion results in metabolic disturbance, changes in cerebral blood flow and perfusion, and several other pathophysiologic

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Complete Concussions Baseline Testing

The concussion space is constantly evolving, and Complete Concussions does our best to continually improve our testing protocols to provide the most sensitive and reliable tests available. As such, we

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Frequently asked
Quick Answers
Baseline testing measures how someone performs before injury, often in areas like symptoms, balance, reaction time, memory, vision, and cognition. If a concussion occurs, the baseline can help guide comparison during recovery.
Absolutely. Baseline testing is helpful, especially for athletes or organizations managing return-to-play decisions. While it is not required to diagnose or treat a concussion, it adds useful objective data when done properly, greatly reducing the risk of repeat injury due to improper return-to-play management.

Baseline testing is most useful for athletes in contact or collision sports, people with prior concussions, and organizations that need clear pre-season data. It should be part of a broader concussion protocol, not a stand-alone tool.

No. Baseline testing does not diagnose concussion by itself. It provides comparison data, but diagnosis should include symptoms, injury mechanism, physical exam, clinical history, and objective testing when appropriate.

Baseline testing should be kept current, especially for growing athletes whose brains, bodies, and academic demands change over time. The ideal timing depends on age, sport, risk level, and the testing system used.

For clinicians & teams
Run baseline, SCAT6, Neurocognitive and return-to-play in one workflow.
NeuroLogic consolidates cognitive testing, postural sway, remote baseline and automated return-to-play into a single platform. Plans for solo providers, clinical teams, schools and sports organizations.
04 / 10

Recovery & Return to Activity

Return-to-learn, return-to-play and return-to-work protocols, grounded in current evidence, and not the old “dark room” playbook.

Concussion Recovery Time: What’s Normal and What’s Not

TL;DR Most people recover within days to about one month when they follow an active, stepwise plan (1). Symptoms persisting beyond 4 weeks suggest persistent symptoms and warrant a multimodal

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Omega-3 Fatty Acids and Concussions: Can They Support Brain Recovery?

Introduction: Can Nutrition Really Impact Concussion Recovery? When it comes to concussion recovery, most people think of rest, rehab, and return-to-play protocols. But what about nutrition? Omega-3 fatty acids, particularly

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TLDR: Pathophysiology of Concussion

What actually happens to the brain during a concussion? Most people think of it as a “bruise,” but that’s not quite accurate. Concussion is a complex functional brain injury involving

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Frequently asked
Quick Answers

Many people improve within days to a few weeks, but recovery varies. Children and teens often recover within a few weeks, while some people need more time and a structured treatment plan.

The first 24 to 48 hours usually involve relative rest, not complete shutdown. After that, light activity can often begin as tolerated, while avoiding high-risk activities that could cause another head injury.

Light physical activity, such as walking, can often begin within the first couple of days if symptoms stay mild and manageable. Exercise should be progressed gradually and adjusted if symptoms worsen.

Return to work or school should be gradual and based on symptoms. Many students can return to school within 1 to 2 days with supports, while work plans should consider screen tolerance, fatigue, focus, and job demands.

An athlete should return to sport only after medical clearance and a stepwise return-to-play progression. If symptoms return at any stage, the athlete should stop, recover, and resume from the previous tolerated step.

05 / 10

Persistent Symptoms & Why They Happen

Cervical, vestibular, autonomic, vision and cognitive drivers of prolonged recovery, and what to do about each. This is Complete Concussions’ clinical wheelhouse.

Brain Fog After Concussion: Why It Happens & How to Treat It

Brain fog after concussion usually comes from a mix of fixable problems, not permanent damage. The most common drivers are visual and vestibular issues, cervical dysfunction, autonomic dysregulation with exercise

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What Is Post-Concussion Syndrome and How Long Does It Last?

Quick answer first Most people recover from a concussion within days to about one month. If symptoms last longer than 4 weeks, many clinicians use the term persistent post-concussion symptoms,

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What Causes Headaches After Concussion?

Introduction: Not Just “Normal” Headaches Headaches are the most common symptom after a concussion, often lingering for days, weeks, or even months. But here’s the key: not all post-concussion headaches

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Frequently asked
Quick Answers

Persistent concussion symptoms can happen when systems such as the neck, vestibular system, vision, sleep, mood, migraine pathways, or exercise tolerance remain irritated. The next step is identifying the main symptom drivers.

Persistent concussion symptoms are symptoms that continue longer than expected and interfere with daily life. They may include headache, dizziness, visual issues, fatigue, brain fog, sleep problems, mood changes, or exercise intolerance.

Symptoms can flare when your current activity level exceeds your recovery capacity. This does not always mean damage is occurring. It often means your plan needs better pacing, graded exposure, or targeted treatment.

Yes. Anxiety can amplify symptoms, increase body tension, disrupt sleep, and make normal sensations feel more alarming. This does not mean symptoms are “just anxiety.” It means emotional and physical recovery should be addressed together.

Consider seeing a concussion-trained clinician or certified provider if symptoms last more than 2 to 4 weeks, worsen with activity, affect school or work, or include dizziness, vision issues, severe headaches, or repeated setbacks.

06 / 10

Long-Term Risk, Repeat Concussions & CTE

The evidence on cumulative impact, neurodegenerative risk and what actually predicts long-term outcomes. Steady, honest, no-panic framing.

Quick Look: How many concussions Is too many?

Introduction: A Question Every Athlete Asks If you or someone you love has had more than one concussion, you’ve probably asked: “How many concussions is too many?” This is one

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How many concussions Is too many?

Updated June 25 2021 Less concussions are generally better than more concussions but, when should an athlete retire? The answer to how many concussions is too many, is not that

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CTE

ACD17 | Delayed Symptoms, Concussion Tracking & CTE

In episode 17, we discussed how and when symptoms of concussion present, addressing some of the challenges in connecting with athletes and injury tracking, and some new research on CTE

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Frequently asked
Quick Answers

Current evidence does not show that one concussion, or occasional head impacts, causes CTE. CTE is more strongly associated with long-term exposure to repeated head impacts, and research is still evolving.

At this time, CTE can only be confirmed after death through specialized brain examination. Researchers are studying ways to identify it during life, but there is no definitive living-patient diagnostic test yet.

A second concussion before full recovery can increase the risk of more severe or longer-lasting symptoms. This is why return-to-play, return-to-work, and return-to-activity decisions should be gradual and clinically guided.

There is no universal number that applies to everyone. Risk depends on recovery time, symptom severity, number of injuries, time between injuries, age, sport, medical history, and the person’s goals and values.

It is reasonable to take concussion history seriously, especially with repeated injuries. The most helpful approach is to reduce future head impacts, treat current symptoms properly, and make sport or work decisions with informed clinical guidance.

07 / 10

Prevention, Helmets & Safety

What the research says, and doesn’t say, about helmets, mouthguards, rule changes and training-load management.

Protecting Athletes: The Truth About Concussion-Reducing Devices

In the past few years, there has been a significant emphasis (and rightly so) on concussion prevention in sports at both professional and amateur levels. Professional sports organizations such as

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Do Helmets and Headgear Prevent Concussions?

As the popularity of contact sports continues to grow, concussion prevention is becoming a hot topic. With millions of youth athletes in the U.S. reporting concussions each year, it’s a

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Helmet and mouthguard sensors: Do they detect concussions?

Recently football teams have made headlines for investing in smart helmets that detect concussions and measure hits. But are these helmets as effective at detecting concussions as they are made

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Frequently asked
Quick Answers

Helmets are exceptional at preventing skull fractures and catastrophic traumatic brain injuries, but they cannot fully eliminate the internal rotational forces that cause the brain to shift and result in a concussion.

Mouthguards are critical for preventing dental and facial injuries. However, the current medical consensus regarding their ability to significantly reduce concussion rates is mixed and generally limited.

Prevention works best when it combines safer rules, proper technique, reduced head-impact exposure, well-fitted equipment, honest symptom reporting, good coaching, and a culture where athletes feel safe speaking up.

Neck strength may help some athletes better control head movement, but it should be viewed as one part of a broader prevention plan. It does not replace rule changes, proper equipment, and safer training environments.

No. If a concussion is suspected, the athlete should be removed from play and assessed. Continuing to play increases the risk of another injury and can make recovery more complicated.

08 / 10

Parents, Schools & Sports Organizations

Practical guidance for non-clinicians: when to worry, what to ask, how to advocate, and how to build safer programs.

Summary: A Parent’s Guide to Concussions

My Child Has a Concussion – Now What? A Parent’s Guide to Concussions No parent wants to hear that their child has a concussion. It can be overwhelming, confusing, and

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What Sport Has The Most Concussions?

Concussions can happen anywhere, but when it comes to sports, some activities carry significantly higher risks than others. As awareness and understanding of concussion injuries continue to evolve, it becomes

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How Long Should the Return-to-Play Process Take for a Student to Complete?

When an athlete suffers a concussion, one of the most common questions from parents and coaches is: “How long will it take for them to return to play?” The answer

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Frequently asked
Quick Answers

Remove the child from play or risky activity, monitor symptoms, watch for danger signs, and arrange assessment with a healthcare provider. Parents should also communicate with coaches, teachers, and school staff.

Many children can return to school within 1 to 2 days with symptom-based supports. A gradual return often helps recovery better than staying home too long without a plan.

Helpful accommodations may include rest breaks, reduced workload, extra time, limited screen exposure, quiet spaces, adjusted testing, sunglasses or light modifications, and a gradual return to full academic demands.

Coaches should remove the athlete immediately, check for danger signs, notify parents or guardians, and keep the athlete out of sport until cleared by a healthcare provider. Return to play is a medical decision.

A strong concussion policy should include education, baseline testing when appropriate, removal-from-play rules, medical referral pathways, return-to-learn and return-to-play steps, documentation, and clear roles for staff, parents, and clinicians.

09 / 10

Clinician Education & Tools

Protocols, charting rubrics, case workflows and implementation guides written for working clinicians: PT, AT, SLP, OT, chiro, MD, and vision therapy. This is the core of our certification curriculum, opened up.

The Importance of Active Rehab Concussion Training for Medical Professionals

If your default plan for concussion is still “rest until symptoms resolve,” you’re running last decade’s playbook. Since 2023, the field has moved toward active, individualized rehabilitation anchored by early,

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What Flavor/Subtype of Concussion Does Your Patient Have? Psychological Type Deep-dive

Which of the Concussion Subtypes are Driving Your Patient’s Symptoms? A Psychological Type Deep-dive Welcome to the last and final part of the deep dive into the 4 different mild

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What Flavor/Subtype of Concussion Does Your Patient Have? Cervical Spine (Vestibulospinal) Type Deep-Dive

The majority of individuals, approximately 60-70%, who sustain a concussion will recover within 4 weeks. While many strive to be among this majority, about 30-40% of concussion patients will experience

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Frequently asked
Quick Answers

A strong assessment includes injury history, symptom profile, neurological screen, cervical exam, vestibular and ocular screening, balance, cognitive function, sleep, mood, exertion tolerance, and risk factors for prolonged recovery.

Useful tools may include symptom scales, balance testing, vestibular/ocular screening, cervical assessment, cognitive screening, exertion testing, and structured return-to-learn, return-to-work, and return-to-play protocols.

Referral is appropriate when symptoms persist, worsen, or involve complex dizziness, vision problems, severe headache, neck dysfunction, mood concerns, exercise intolerance, multiple concussions, or difficulty returning to school, work, or sport.

Common gaps include over-relying on imaging, under-assessing the neck, missing vestibular or visual drivers, recommending too much rest, delaying active rehab, and failing to provide a clear return-to-activity plan.

A helpful explanation is: “Your scan rules out many serious structural problems, but it does not measure every function affected by concussion. Your symptoms are real, and we can test the systems that may be driving them.”

For clinicians
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10 / 10

News & Announcements

Company updates, new feature releases for NeuroLogic, and announcements from the Complete Concussions network.

Complete Concussions Partners with The Cyclists’ Alliance

We are proud to announce our partnership with The Cyclists’ Alliance (TCA), the independent voice of women’s professional cycling. This matters to us because concussion care should not depend on

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Bendigo Concussion Clinic Shows the Impact of Local Concussion Care

The Bendigo Concussion Clinic, newly certified as part of the Complete Concussions network, has rapidly become a lifeline for regional athletes. According to an ABC News report, the clinic is

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Complete Concussions Expands Concussion Care Solutions in Australia & New Zealand with CXDX Partnership

Revolutionizing Concussion Treatment for Athletes, Schools & Healthcare Providers in Oceania Sydney, Australia – Thursday 16th January 2025 Complete Concussions, a global leader in concussion care and treatment, is excited

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