By Benjamin McCay, DC, CCSP

Published July 10, 2026

 

A concussion can occur during a motor vehicle accident even when the head never strikes the steering wheel, dashboard, window, or headrest. A direct blow to the head can cause a concussion, but so can a forceful hit to the body that makes the head and brain move rapidly.

A concussion is a type of mild traumatic brain injury (mTBI). Despite the word mild, symptoms can interfere with work, school, driving, sleep, and everyday activities.

Symptoms are not always obvious immediately after a collision. Headaches, dizziness, brain fog, memory problems, nausea, or difficulty concentrating may appear or become more noticeable over the following hours or days.

Because a concussion is a brain injury, symptoms that may indicate concussion should be evaluated by an appropriate medical provider. Prompt evaluation is especially important when symptoms are severe, worsening, or accompanied by neurological warning signs.

 

What Is a Concussion?

A concussion is a type of mild traumatic brain injury (mTBI) caused by a biomechanical force that disrupts normal brain function.

Concussion primarily produces a temporary disturbance in how the brain functions. Conventional CT scans and MRI often appear normal because these studies are designed mainly to identify visible structural injuries, such as bleeding, fractures, or significant swelling. A normal scan does not exclude a concussion or mean that the patient's symptoms are not real.

Most people improve over time, but recovery varies. Some recover within days or weeks, while others experience symptoms that last longer and require additional medical evaluation or rehabilitation.

What Is the Difference Between mTBI and TBI?

Traumatic brain injury (TBI) is the broad medical term for an injury that affects how the brain functions. TBI is commonly classified as mild, moderate, or severe.

A mild traumatic brain injury (mTBI) is the least severe category of TBI. A concussion is a clinical form of mTBI, and the terms concussion and mTBI are often used interchangeably in patient care.

The relationship can be summarized this way:

Every concussion is a traumatic brain injury, but not every traumatic brain injury is a concussion.

TBI severity is usually classified according to the patient's condition shortly after the injury. Clinicians commonly consider:

• Level of consciousness
• Duration of any loss of consciousness
• Duration of confusion or memory loss
• Neurological findings
• Glasgow Coma Scale score

These initial severity labels do not always predict how disruptive the symptoms will be or how long recovery will take.

Mild Traumatic Brain Injury

An mTBI may involve:

• Brief confusion or disorientation
• Memory loss surrounding the accident
• A brief loss of consciousness—or no loss of consciousness
• Headache, dizziness, brain fog, nausea, or difficulty concentrating
• Normal conventional CT or MRI findings, which are common

The term mild refers to the initial clinical classification of the injury. It does not mean that symptoms are unimportant or that recovery will always be rapid.

Some people recover within days or weeks. Others experience persistent headaches, dizziness, cognitive difficulties, sleep disruption, mood changes, or reduced tolerance for work and daily activities.

Moderate or Severe Traumatic Brain Injury

Moderate and severe traumatic brain injuries generally involve greater neurological impairment at the time of injury.

A commonly used classification based on the Glasgow Coma Scale is:

• Mild TBI: GCS score of 13–15
• Moderate TBI: GCS score of 9–12
• Severe TBI: GCS score of 3–8

Healthcare providers also consider the duration of unconsciousness, memory loss, confusion, neurological abnormalities, and imaging findings. The classification describes the patient's initial clinical condition and is not determined by imaging alone.

Moderate or severe TBI may involve:

• Longer loss of consciousness
• Prolonged memory loss or confusion
• Lower Glasgow Coma Scale scores
• Significant weakness, speech difficulty, or other neurological findings
• Brain swelling or increased pressure within the skull
• Structural brain injury visible on CT or MRI
• Hospitalization, surgery, or extended rehabilitation

These injuries carry a greater risk of lasting disability and life-threatening complications.

Epidural and Subdural Hematomas

Motor vehicle trauma can also cause bleeding inside the skull. Two important types are epidural hematoma and subdural hematoma.

An epidural hematoma is a collection of blood between the skull and the dura, the tough outer covering of the brain. The bleeding can enlarge rapidly, compress the brain, and cause sudden neurological deterioration. Some epidural hematomas require emergency surgery.

A subdural hematoma is a collection of blood between the dura and the arachnoid membrane surrounding the brain. Acute subdural hematomas may occur when veins or other blood vessels are torn during rapid acceleration, deceleration, or direct head trauma. They may occur along with injury to the underlying brain and can also cause dangerous pressure within the skull.

Epidural and subdural hematomas are traumatic intracranial hemorrhages, not strokes.

The presence of either hematoma does not, by itself, determine whether the TBI is mild, moderate, or severe. Severity is based primarily on the patient's neurological condition.

For example:

• A small hematoma in a fully alert patient with a Glasgow Coma Scale score of 13–15 may still be classified clinically as a mild TBI with an imaging abnormality, sometimes called a complicated mild TBI.
• A hematoma associated with impaired consciousness, neurological deterioration, brain compression, or a lower Glasgow Coma Scale score may be classified as a moderate or severe TBI.

Regardless of its formal severity classification, any epidural or subdural hematoma is a serious finding that requires immediate medical evaluation, close monitoring, and sometimes neurosurgical treatment.

Why the Terminology Matters

Patients sometimes hear the word mild and assume that an mTBI does not require medical attention. That is not correct.

A person with suspected mTBI may still require prompt evaluation to assess for bleeding, skull fracture, cervical spine injury, or another serious condition. Symptoms can also change during the hours or days following an accident.

Concussion and mTBI should therefore be taken seriously, particularly when symptoms are worsening, persistent, or interfering with normal activities.

Can You Get a Concussion Without Hitting Your Head?

Yes.

Many people are surprised to learn that direct head impact is not required for a concussion to occur.

During a rear-end collision, for example, the head is rapidly thrown backward and then forward in a matter of milliseconds. These acceleration and deceleration forces can cause the brain to move within the skull, temporarily disrupting normal brain function even when the head never contacts another object.

Concussions may occur during:

• Rear-end collisions
• Front-end collisions
• Side-impact (T-bone) collisions
• Rollover accidents

The absence of visible vehicle damage or direct head impact does not rule out a concussion. Healthcare providers determine whether a concussion is likely based on the patient's history, symptoms, and clinical examination—not simply by whether the head struck something during the crash.

Why Concussions Can Be Difficult to Recognize

Unlike a broken bone or a deep cut, a concussion often has no outward signs of injury.

Many patients:

• Never lose consciousness
• Remember the accident clearly
• Walk away from the scene feeling "fine"
• Do not seek medical attention until symptoms appear later

In fact, loss of consciousness occurs in only a minority of concussions. Many patients experience more subtle symptoms that gradually become noticeable over the next several hours or days.

For this reason, anyone who develops persistent headaches, dizziness, confusion, memory difficulties, or other neurological symptoms following a motor vehicle accident should be medically evaluated.

Common Concussion Symptoms

Concussion symptoms vary considerably from person to person. The Centers for Disease Control and Prevention (CDC) groups symptoms into four broad categories: physical, cognitive, emotional, and sleep-related. Patients may experience symptoms from one or several of these categories.

Physical Symptoms

Physical symptoms commonly include:

• Headache
• Neck pain
• Dizziness
• Balance problems
• Nausea or vomiting
• Blurred or double vision
• Sensitivity to light
• Sensitivity to noise
• Ringing in the ears (tinnitus)
• Fatigue
• Feeling slowed down

Cognitive Symptoms

Cognitive symptoms affect how the brain processes information and may include:

• Difficulty concentrating
• Memory problems
• Feeling mentally "foggy"
• Slowed thinking
• Difficulty finding words
• Confusion
• Difficulty learning new information
• Reduced attention span

Many patients describe these symptoms simply as brain fog.

Emotional Symptoms

Changes in mood are also common after a concussion.

Symptoms may include:

• Irritability
• Anxiety
• Depression
• Mood swings
• Increased emotional sensitivity
• Nervousness

Family members are often the first to notice these changes.

Sleep-Related Symptoms

Concussions frequently disrupt normal sleep patterns.

Patients may experience:

• Sleeping more than usual
• Sleeping less than usual
• Difficulty falling asleep
• Difficulty staying asleep
• Excessive daytime sleepiness
• Feeling tired despite a full night's sleep

Because sleep plays an important role in recovery, persistent sleep disturbances should be discussed with your healthcare provider.

Delayed Concussion Symptoms

Concussion symptoms are not always immediately apparent.

After a motor vehicle collision, a person may be focused on the accident scene, vehicle damage, other injuries, or the stress of the event. Some symptoms may also evolve or become easier to recognize over the following hours or days.

Patients commonly report:

• Persistent or worsening headaches
• Brain fog
• Difficulty concentrating
• Memory problems
• Dizziness
• Fatigue
• Neck pain
• Nausea
• Increased sensitivity to light or noise

Some people notice symptoms immediately. Others do not recognize problems until later that day or several days after the collision.

Because symptoms may be delayed, monitor yourself after a significant motor vehicle accident and seek medical evaluation if neurological symptoms appear or worsen.

When Should You Go to the Emergency Room?

Although most concussions are not life-threatening, some symptoms may indicate a more serious brain injury requiring immediate medical attention.

Seek emergency medical care immediately if you experience:

• Loss of consciousness
• Repeated vomiting
• Severe or worsening headache
• Increasing confusion or unusual behavior
• Difficulty speaking or understanding speech
• Weakness or numbness in an arm or leg
• Difficulty walking or maintaining balance
• Unequal pupils
• Seizures
• Significant vision changes
• Increasing drowsiness or inability to awaken
• Clear fluid draining from the nose or ears

These symptoms may indicate bleeding within the brain, increased pressure inside the skull, or another serious neurological injury that requires urgent evaluation.

If you are uncertain whether your symptoms represent an emergency, it is safest to seek immediate medical attention.

How Is a Concussion Evaluated?

A concussion is diagnosed by an appropriate medical provider using the patient's history, symptoms, and physical examination.

The evaluation typically includes questions about:

• How the injury occurred
• Whether there was loss of consciousness
• Memory before and after the accident
• Current symptoms
• Previous concussions
• Medications and medical history

The neurological examination may include assessment of:

• Orientation and memory
• Attention and concentration
• Balance
• Coordination
• Eye movements
• Cranial nerve function
• Reflexes
• Strength and sensation

Healthcare providers may also use standardized concussion assessment tools to help document symptoms and monitor recovery over time.

Because concussion symptoms frequently overlap with injuries involving the cervical spine, a thorough examination often includes evaluation of the neck as well.

Why Whiplash and Concussion Are Both Evaluated

Many symptoms that develop after a car accident can originate from either the brain, the cervical spine, or both.

For example, the following symptoms may occur with a concussion, whiplash, or a combination of both:

• Headaches
• Dizziness
• Neck pain
• Difficulty concentrating
• Balance problems
• Visual discomfort

Distinguishing between these injuries is important because treatment recommendations may differ. A comprehensive evaluation helps determine whether symptoms are most consistent with a concussion, a musculoskeletal injury such as whiplash, or both.

Will a CT Scan Show a Concussion?

Usually not.

A CT (computed tomography) scan is excellent for identifying serious injuries such as:

• Bleeding within the brain
• Skull fractures
• Significant swelling
• Other life-threatening traumatic injuries

However, most uncomplicated concussions appear normal on a CT scan. CT is primarily used to identify structural injury rather than to diagnose concussion.

For this reason, a normal CT scan does not rule out a concussion.

CT scans are generally performed when a healthcare provider suspects a more serious injury or when certain high-risk symptoms are present.

Will an MRI Show a Concussion?

Not necessarily.

Like CT scans, MRI (magnetic resonance imaging) is designed to evaluate structural abnormalities within the brain.

Most patients with an uncomplicated concussion have a normal conventional MRI because routine MRI usually does not show the functional or microscopic changes associated with concussion.

An MRI may be recommended when:

• Symptoms persist longer than expected
• Symptoms worsen over time
• Another neurological condition is suspected
• Additional evaluation is needed after the initial injury

A normal MRI does not mean that a patient's symptoms are not real or that a concussion did not occur.

Can Imaging Rule Out a Serious Brain Injury?

Imaging can identify or help exclude many serious structural brain injuries, but no single scan rules out every possible brain injury.

Although CT scans and MRI often appear normal after a concussion, they are extremely valuable for identifying conditions that require immediate treatment, including:

• Brain hemorrhage
• Skull fractures
• Significant brain swelling
• Other traumatic injuries

This is why patients with severe symptoms or concerning neurological findings are often referred for emergency imaging, even though the concussion itself may not be visible on the scan.

Whiplash vs. Concussion: What's the Difference?

Whiplash and concussion are different injuries, but they frequently occur together during a motor vehicle accident.

A concussion is a mild traumatic brain injury caused by rapid movement of the brain within the skull.

Whiplash is a musculoskeletal injury involving the muscles, ligaments, joints, fascia, discs, and other soft tissues of the cervical spine. During a collision, the head and neck are rapidly accelerated and decelerated, placing significant stress on these structures.

Because the same forces that can cause a concussion also commonly cause whiplash, many patients experience both injuries simultaneously.

Concussion	Whiplash
Brain injury	Neck injury
Primarily affects brain function	Primarily affects muscles, ligaments, joints, and other cervical tissues
May cause cognitive and neurological symptoms	Primarily causes musculoskeletal symptoms
Requires appropriate medical evaluation	May benefit from conservative musculoskeletal treatment after appropriate evaluation

Can Whiplash Cause Symptoms That Feel Like a Concussion?

Yes.

One of the reasons concussion can be difficult to recognize after a car accident is that injuries involving the cervical spine can produce many of the same symptoms.

Research has shown that neck injuries may contribute to symptoms including:

• Headaches
• Dizziness
• Neck pain
• Visual discomfort
• Difficulty concentrating because of pain
• Balance disturbances
• Fatigue

These symptoms may result from:

• A concussion
• A cervical spine injury
• Or a combination of both

For example, an injured cervical joint or muscle may produce a cervicogenic headache, while irritation of structures in the upper cervical spine may contribute to dizziness or balance problems.

Because of this overlap, symptoms should not automatically be attributed to only the brain or only the neck. A comprehensive evaluation helps determine which structures are contributing to a patient's symptoms.

Why Neck Pain Should Never Be Ignored

Neck pain is one of the most common complaints after a motor vehicle accident and frequently accompanies concussion.

Common symptoms of whiplash include:

• Neck pain
• Muscle tightness
• Reduced range of motion
• Shoulder pain
• Upper back pain
• Headaches
• Muscle spasms

Fortunately, many of these musculoskeletal injuries respond well to conservative treatment.

Addressing neck dysfunction may also improve symptoms such as cervicogenic headaches, muscle tension, and restricted movement that commonly develop following a collision.

How Long Does It Take to Recover From a Concussion?

Recovery varies considerably from person to person.

Many people recover within several weeks, while others require months before symptoms completely resolve.

Recovery depends on many factors, including:

• Severity of the injury
• Previous concussions
• Age
• Overall health
• Associated injuries
• Whether whiplash or other musculoskeletal injuries are also present

Although most patients improve over time, recovery is not always linear. Some days may be better than others, particularly during the early stages of healing.

What Does Recovery Typically Involve?

Current medical guidelines generally recommend relative rest during the first 24 to 48 hours after a concussion rather than prolonged bed rest.

As symptoms improve, patients are usually encouraged to gradually resume normal daily activities under the guidance of their healthcare provider.

Recovery often includes:

• Gradual return to work, school, or play
• Progressive increase in physical activity as tolerated
• Symptom monitoring
• Follow-up with the appropriate healthcare provider
• Management of associated injuries, such as whiplash

Returning too quickly to strenuous physical or cognitive activity may worsen symptoms or delay recovery.

What Is Second Impact Syndrome?

Second Impact Syndrome (SIS) is a rare and debated condition that has been described primarily in adolescents and young athletes. It is proposed to occur when a person sustains another head injury before fully recovering from an earlier concussion, followed by rapid brain swelling and severe neurological deterioration.

Because confirmed cases are uncommon and much of the published evidence is based on case reports, the exact mechanism and even the diagnostic boundaries of SIS remain controversial.

The practical safety message is clear: another head injury before recovery can be dangerous. A person recovering from a concussion should avoid contact sports and other activities with a meaningful risk of another blow, collision, or fall until an appropriate medical provider has cleared the return to those activities.

Following a motor vehicle accident, this may include temporarily avoiding contact sports, high-risk recreation, or work tasks that create a substantial risk of another head injury.

What Are Persistent Post-Concussion Symptoms?

Most people improve after a concussion, but some continue to experience symptoms for weeks or months. These are often called persistent post-concussion symptoms or post-concussion syndrome (PCS).

Symptoms may include:

• Headaches
• Brain fog
• Difficulty concentrating
• Memory problems
• Dizziness
• Fatigue
• Sleep disturbances
• Anxiety, irritability, or depression

Persistent symptoms do not always come from a single source. Contributing factors may include the concussion itself, cervical spine injury, vestibular dysfunction, migraine, sleep disturbance, mood symptoms, or a combination of these problems.

An appropriate healthcare provider may recommend additional evaluation or referral to neurology, neuropsychology, vestibular rehabilitation, vision care, physical therapy, or other specialists based on the patient's specific symptoms.

Why Follow-Up Care Is Important

Concussion symptoms often improve gradually, making follow-up appointments an important part of recovery.

Regular follow-up allows healthcare providers to:

• Monitor symptom progression
• Identify persistent or worsening symptoms
• Guide a gradual return to normal activities
• Determine whether additional testing or specialist referral is appropriate

Patients should also continue to report any new or worsening neurological symptoms, especially if they develop after the initial evaluation.

Although most people recover fully, ongoing symptoms deserve careful attention rather than being dismissed as "normal" after a car accident.

Can Chiropractic Care Help After a Concussion?

A concussion is a brain injury and should be evaluated and managed by an appropriate medical provider.

At Advanced Chiropractic & Massage, we do not diagnose or treat concussion. When a patient's history or symptoms raise concern for concussion or another neurological injury, we recommend evaluation by an appropriate medical provider. Chiropractic care is directed toward associated musculoskeletal injuries.

Many patients who sustain a concussion during a motor vehicle accident also have musculoskeletal injuries involving the neck, muscles, ligaments, joints, fascia, discs, and other soft tissues.

These associated injuries may contribute to:

• Neck pain
• Whiplash symptoms
• Muscle tension
• Cervicogenic headaches
• Reduced cervical mobility
• Joint stiffness

After appropriate medical evaluation and once urgent neurological injury has been addressed, conservative care may help manage the associated musculoskeletal injuries.

Treatment is individualized and may include chiropractic care, soft-tissue treatment, massage therapy, rehabilitative exercise, or referral to other healthcare providers when appropriate.

When Should You See a Chiropractor After a Car Accident?

Even relatively low-speed collisions can produce injuries that are not immediately obvious.

If you develop any of the following after a motor vehicle accident, you should be evaluated by a healthcare provider:

• Neck pain
• Back pain
• Headaches
• Muscle stiffness
• Reduced range of motion
• Pain that worsens over the next several days

If you also experience symptoms that may be consistent with a concussion—such as dizziness, brain fog, memory problems, confusion, or balance difficulties—you should first receive appropriate medical evaluation.

Once serious neurological injury has been evaluated, chiropractic care may help address the associated musculoskeletal injuries that commonly accompany motor vehicle accidents.

Concussion, Whiplash, and Neck Pain After a Car Accident in Everett and Lynnwood

At Advanced Chiropractic & Massage, we evaluate musculoskeletal injuries following motor vehicle accidents, including neck pain, headaches, stiffness, reduced mobility, and other symptoms associated with whiplash.

Because concussion and cervical spine injuries can produce overlapping symptoms, we assess the musculoskeletal injuries while remaining alert for findings that require medical referral.

When a patient's history or symptoms raise concern for concussion or another neurological injury, we recommend prompt evaluation by an appropriate medical provider.

After serious neurological injury has been appropriately evaluated, treatment can focus on musculoskeletal conditions such as whiplash, cervical sprain and strain injuries, joint dysfunction, muscle tension, and cervicogenic headaches.

Patients from Everett, Lynnwood, and surrounding communities may seek care at our Everett clinic for evaluation and treatment of musculoskeletal injuries following a motor vehicle collision.

Frequently Asked Questions

Can you have a concussion without hitting your head?

Yes. A concussion may occur from the rapid acceleration and deceleration forces of a motor vehicle collision, even if your head never strikes the steering wheel, dashboard, window, or another object.

How long after a car accident can concussion symptoms appear?

Symptoms may begin immediately, several hours later, or even a few days after the collision. Delayed symptoms are common, which is why it is important to monitor yourself closely after an accident.

Does everyone lose consciousness after a concussion?

No.

Most people with a concussion do not lose consciousness. Many remain awake throughout the accident and are able to walk away from the scene before symptoms gradually develop.

Will a concussion show up on a CT scan or MRI?

Usually not.

Most uncomplicated concussions do not produce abnormalities visible on conventional CT scans or MRI. These studies are primarily used to identify structural injuries such as bleeding, skull fractures, or significant swelling rather than to diagnose concussion.

Can whiplash and a concussion happen together?

Yes.

The same forces that cause a concussion commonly injure the cervical spine. As a result, many patients experience both a concussion and whiplash following a motor vehicle accident.

Can neck injuries cause symptoms similar to a concussion?

Yes.

Whiplash injuries may contribute to headaches, dizziness, neck pain, fatigue, balance problems, and difficulty concentrating. Because these symptoms overlap with concussion, a thorough evaluation is important to determine the source of a patient's symptoms.

Should I drive if I think I have a concussion?

If you are experiencing dizziness, slowed thinking, blurred vision, impaired concentration, or other symptoms that may indicate a concussion, avoid driving until you have been evaluated and cleared by an appropriate medical provider.

When should I seek emergency medical care?

Seek immediate emergency care if you experience:

• Loss of consciousness
• Repeated vomiting
• Severe or worsening headache
• Increasing confusion
• Weakness or numbness
• Difficulty speaking
• Seizures
• Unequal pupils
• Significant vision changes
• Difficulty walking
• Increasing drowsiness or inability to awaken

These symptoms may indicate a more serious brain injury requiring urgent medical evaluation.