Concussion Symptoms, Red Flags, and Recovery: What You Need to Know

A hard hit on the field. A fall at home. A fender bender on the drive to work. Concussions can happen in an instant, and knowing what to watch for afterward can make a real difference in how quickly and safely someone recovers.

According to the CDC, a concussion is a type of traumatic brain injury caused by a bump, blow, or jolt to the head, or by a hit to the body that causes the head and brain to move rapidly back and forth. That rapid movement causes the brain to shift inside the skull, which can disrupt normal brain function and trigger a wide range of symptoms.

At OC Sports & Rehab, our providers specialize in concussion rehabilitation, and we see firsthand how much confusion still exists around what a concussion looks like and when it becomes an emergency. This guide breaks down the symptoms, the warning signs that require immediate medical attention, and what a safe recovery actually looks like.

What Are the Symptoms of a Concussion?

Concussion symptoms vary from person to person depending on the severity and location of the impact, and they don’t always appear right away. Some symptoms show up within minutes, while others may not surface for hours or even a day or two after the injury.

Symptoms the Injured Person May Feel

Headache or pressure in the head
Nausea or vomiting
Dizziness or balance problems
Sensitivity to light or noise
Feeling sluggish, hazy, foggy, or groggy
Confusion or difficulty concentrating
Memory problems
Neck pain

Signs Others May Notice

Parents, coaches, and colleagues often spot concussion signs before the injured person does. Watch for:

Appearing dazed or stunned
Confusion about events, instructions, or surroundings
Answering questions slowly or repeating the same questions
Forgetting recent conversations or instructions
Moving in a clumsy or uncoordinated way
Noticeable mood or personality changes

Because symptoms can evolve over the following hours and days, ongoing observation matters just as much as the initial assessment.

Emergency Red Flags: When to Go to the ER Immediately

Most concussions do not require emergency care, but certain symptoms indicate a more serious brain injury that needs immediate evaluation. Call 911 or go to the nearest emergency room right away if you notice any of the following after a bump, blow, or jolt to the head:

Loss of consciousness, even briefly
One pupil larger than the other
A headache that gets worse and does not go away
Repeated vomiting or nausea
Slurred speech
Weakness, numbness, or decreased coordination
Increasing confusion, restlessness, or agitation
Seizures or convulsions
Inability to recognize people or places
Unusual behavior or extreme drowsiness

These red flags are consistent with guidance used by emergency medicine providers and pediatric concussion specialists, and they should never be managed at home. When in doubt, seek medical evaluation rather than waiting to see if symptoms improve on their own.

Concussion Protocols: What to Do Right After the Injury

If your child, athlete, or anyone else sustains a fall or hit to the head, neck, or back, remove them from play or activity immediately and keep them out until they’ve been evaluated by a medical professional. This rule applies whether the injury happens during a game, at home, or at work. There’s no such thing as a “minor” head injury that can be safely ignored.

A few important points about the immediate aftermath:

No sport is entirely risk-free. All physical activity carries some inherent risk of head injury, and that risk shouldn’t be dismissed based on which sport or activity was involved.
Symptoms can worsen over time. While many symptoms appear soon after the injury, it’s possible for them to intensify over the following hours or days, which is why monitoring matters.
Recovery timelines vary widely. Some people feel better within a few days, while more significant concussions can produce symptoms lasting a month or longer.
Only a medical professional should clear return to activity. Whether the evaluation happens at urgent care, an emergency room, or a primary care office, a qualified provider should be the one to determine when it’s safe to resume normal activity.

What Recovery From a Concussion Actually Looks Like

Concussion recovery isn’t one-size-fits-all, and outdated advice about total darkness and complete inactivity has largely been replaced by more nuanced, evidence-based guidance. A modern recovery plan typically includes:

Brief initial rest: A short period of physical and cognitive rest, usually 24 to 48 hours, followed by a gradual return to light activity rather than prolonged, complete rest.
Gradual return to activity: A step-by-step progression back to school, work, and physical activity, increasing intensity only as symptoms allow.
Symptom management: Addressing specific symptoms like headaches, dizziness, or neck pain through targeted treatment rather than waiting for them to resolve on their own.
Vestibular and balance therapy: Many concussions affect the inner ear and balance system, and targeted rehabilitation exercises can significantly speed up recovery.
School or work accommodations: Temporary adjustments like reduced screen time, extra breaks, or lighter workloads while cognitive symptoms resolve.
Ongoing professional monitoring: Regular check-ins with a provider to track progress and adjust the recovery plan as needed.

Most people begin feeling better within one to two weeks, but every recovery timeline is different, and rushing back into full activity too soon can prolong symptoms or increase the risk of a more serious injury.

Why Concussion Awareness Has Grown So Much

Public awareness around concussions has increased significantly over the past decade, driven by both rising diagnosis rates across sports and ages, as well as ongoing media coverage. A pivotal moment came from a 2017 study published in the medical journal JAMA, which found chronic traumatic encephalopathy, commonly known as CTE, in 99% of examined brains from deceased former NFL players. The study defined CTE as a progressive neurodegenerative condition associated with repetitive head trauma.

The findings suggested that repeated head injuries sustained over the course of a career can contribute to more severe neurological changes later in life, with level of play as one contributing factor. Athletes who competed professionally showed a higher likelihood of developing CTE and related conditions compared to those who played only through high school or college. This doesn’t mean every professional athlete will develop CTE, but the correlation was significant enough that it couldn’t be ignored.

In response to mounting public and scientific scrutiny, the NFL formally implemented updated concussion protocols in December 2017, and professional and collegiate programs across other sports have continued to refine their own return-to-play policies since. It’s an ongoing effort, not a solved problem, but it represents meaningful progress toward protecting athletes at every level.

Concussions Deserve to Be Taken Seriously

A concussion is a real injury, not something to shrug off or wait out. This is especially true if it isn’t the person’s first head injury, since repeated concussions can compound recovery time and long-term risk. Coaches, athletes, parents, and medical professionals all share responsibility for recognizing the signs, understanding proper protocols, and following through on them consistently.

Our providers at OC Sports & Rehab specialize in concussion rehabilitation therapy, helping patients recover safely and return to their normal activities with confidence. If you or a loved one has sustained a concussion, reach out to our team today for expert guidance and personalized care.

OC Sports & Rehab
(949) 716-5050

Frequently Asked Questions

How long does it take to recover from a concussion?
Most people begin feeling better within one to two weeks, though recovery time varies based on the severity of the injury, age, and overall health. Some concussions can produce symptoms that last a month or longer, which is why ongoing professional evaluation matters throughout recovery.

Can you have a concussion without losing consciousness?
Yes. Most concussions do not involve a loss of consciousness. Symptoms like headache, confusion, dizziness, and memory problems are far more common indicators of a concussion than blacking out.

Is it safe to sleep after a concussion?
Yes, sleep is generally safe and important for recovery. The old advice to wake someone up repeatedly throughout the night has largely been replaced by guidance allowing normal sleep, unless a medical provider has specific concerns based on the injury.

When can someone return to sports after a concussion?
Return to play should only happen after clearance from a qualified medical professional, following a gradual, symptom-guided progression back to physical activity. Returning too soon significantly increases the risk of a repeat injury and prolonged recovery.

Can a concussion be seen on a CT scan or MRI?
Typically, no. Concussions usually don’t show up on standard imaging like CT scans or MRIs, since they affect brain function rather than causing visible structural damage. Imaging is generally used to rule out more serious injuries like bleeding or skull fractures, not to confirm a concussion.

What’s the difference between a concussion and a more serious brain injury?
A concussion is considered a mild traumatic brain injury, while more serious injuries can involve bleeding, swelling, or structural damage to the brain. Red flag symptoms like repeated vomiting, seizures, worsening headache, or loss of consciousness suggest the possibility of a more serious injury and require emergency evaluation.

Can physical therapy help with concussion recovery?
Yes. Physical therapists trained in concussion rehabilitation can address common post-concussion issues like dizziness, balance problems, neck pain, and difficulty tolerating physical activity, helping guide a safe, structured return to normal function.