How to Test for Concussion: A Practical, Evidence-Based Guide

Recognizing Possible Concussion

A concussion is a biological process affecting the brain, often triggered by a bump, blow, or jolt to the head or body that causes the head and brain to move rapidly back and forth. Signs and symptoms can appear immediately or develop over hours. Key changes to watch for include physical symptoms such as headache, dizziness, nausea or vomiting, blurred or double vision, sensitivity to light or noise, and balance problems; cognitive symptoms like feeling slowed down, confusion, difficulty concentrating or remembering new information, and appearing dazed or stunned; emotional changes such as irritability, sadness, or nervousness; and sleep disturbances including sleeping more or less than usual or having trouble falling asleep. No imaging test can reliably confirm a concussion, so recognition depends on observed changes and reported symptoms. If symptoms worsen or new ones appear—especially repeated vomiting, seizures, weakness, slurred speech, or loss of consciousness—seek immediate medical care.

Immediate Action Steps and Who Should Test

Remove from Play and Protect from Further Injury

When a concussion is suspected, the first step is removal from the activity or environment where another head injury could occur. Athletes should not return to play on the same day until cleared by an appropriate clinician. Coaches, officials, parents, teammates, and healthcare providers all share responsibility in ensuring this happens. Return to school, work, and physical activity should follow a medically supervised, stepwise plan designed to avoid making symptoms worse.

Use a Validated Concussion Assessment Tool

Clinicians and sideline personnel often use standardized assessment tools to evaluate possible concussion. These tools help structure observation and questioning, but they do not diagnose concussion on their own. Positive findings or symptom reports using these tools should prompt referral to a qualified healthcare professional for diagnosis and management. Common tools include the Sport Concussion Assessment Tool (SCAT6 for athletes aged 13 and older), Child SCAT6 for ages 5–12, and the Concussion Recognition Tool (CRT) or Head Injury Assessment in rugby contexts. In younger children, validated checklists for parents and clinicians are used to capture changes in behavior, activity level, and symptoms.

Objective Testing and Clinical Evaluation

Clinical History and Symptom Reporting

A thorough clinical evaluation starts with a clear description of the injury mechanism and a detailed report of symptoms. Clinicians will ask about the force of impact, whether there was a loss of consciousness or vomiting soon after the injury, and whether symptoms such as headache, dizziness, or confusion emerged right away or developed later. They will also review the athlete’s medical, migraine, and psychiatric history, because these can affect symptom presentation and recovery. Honest and detailed symptom reporting is essential; under- or over-reporting can lead to inappropriate return-to-activity decisions.

Physical and Neurological Examination

The clinician will perform a focused physical and neurological exam to assess alertness, orientation, memory, balance, coordination, and cranial nerve function. They may check visual tracking, reaction time, and gait, particularly if balance problems are reported. Vestibular and cervical involvement are common after concussion and influence treatment. In settings with advanced support, clinicians may use tools like the Balance Error Scoring System or computerized dynamic posturography to quantify postural control, though these are typically part of comprehensive evaluations rather than sideline assessments.

Cognitive Testing and Screening

Brief cognitive screens are commonly used to estimate orientation and memory shortly after injury. Items such as asking the athlete to state the current month, day, and year, or to remember and later recall a short list, help detect immediate cognitive deficits. Standardized computerized neurocognitive tests, when available and interpreted by trained professionals, can provide baseline measures and post-injury comparisons. However, these tests are only one part of the overall evaluation and should not be used alone to rule out concussion.

• Orientation: person, place, time, event
• Immediate memory: recall of words or objects
• Concentration: serial tasks or backward spelling
• Balance and coordination: tandem gait, finger-to-nose testing

Imaging and Medical Testing

When Imaging Is Used

Brain imaging such as computed tomography (CT) or magnetic resonance imaging (MRI) is not used to diagnose concussion, because concussion involves physiological function rather than structural damage visible on routine scans. However, clinicians may order imaging if there are red flags that suggest a more serious injury, such as a skull fracture, intracranial bleeding, or significant brain swelling. These red flags include worsening headache, repeated vomiting, seizures, weakness or numbness, slurred speech, loss of consciousness for a prolonged period, or clear fluid draining from the nose or ears.

What to Expect From Testing

When imaging is performed, a CT scan is often the first choice in emergency settings due to speed and wide availability, while MRI provides higher-resolution detail for certain concerns but takes longer and is less practical acutely. Normal imaging does not rule out concussion; conversely, abnormal findings on imaging do not confirm concussion and may reflect unrelated or pre-existing conditions. Decisions to image are guided by validated clinical decision rules, which balance the small risk of serious injury against the risks and costs of unnecessary testing.

Return to Activity and Monitoring

Stepwise Return to Play Protocol

After a suspected concussion, an athlete should not return to full participation until they are symptom-free at rest and gradually reintroduced to activity under medical supervision. A typical protocol progresses from light aerobic exercise, to sport-specific exercise, to non-contact training, to full practice participation, and finally to competition. Each step should be separated by at least 24 hours, and any recurrence of symptoms should prompt stopping, resting, and reassessing with a clinician.

Academic and Workplace Considerations

Young athletes often need coordinated return-to-learn planning, which may include temporary academic adjustments such as reduced screen time, extended deadlines, rest breaks, and a lighter course load. Adults returning to work may require similar accommodations, especially in jobs that demand high concentration or physical effort. The overall goal is to support recovery while minimizing deconditioning and educational or occupational disruption, guided by a clinician’s recommendations.

When to Seek Immediate Care and Red Flags

Even when initial testing suggests a mild injury, certain signs require urgent medical evaluation. These include any deterioration in consciousness, persistent vomiting, severe or worsening headache, new or worsening weakness or numbness, vision changes, extreme drowsiness or difficulty waking, slurred speech, or convulsions. In remote or prehospital settings, emergency medical services should be activated for any of these red flags. When in doubt, err on the side of caution and seek care promptly.

Summary and Practical Takeaways

Testing for concussion begins with recognizing signs and symptoms, followed by immediate removal from activity and use of validated assessment tools by trained personnel. Objective testing and clinical evaluation help determine the presence and severity of injury, while imaging is reserved for suspected structural complications. Recovery is managed through a medically supervised, stepwise return to activity and necessary accommodations at school or work. Recognizing red flags and knowing when to seek urgent care are essential parts of safe concussion management.