Concussion Signs After a Car Crash: What to Watch For

By the Kessler Spine & Rehab Clinical Team

A car crash can jolt the head and body suddenly. Afterward, people sometimes wonder whether a headache, fogginess, or trouble sleeping could be related to a concussion. This guide covers what a concussion is, the symptoms people commonly report, and the warning signs that need emergency care.

Educational, not medical advice. This article is general information and doesn't replace an exam by a qualified provider.

⚠️ Call 911 or go to the ER right away for any of these: a headache that gets worse and does not go away, repeated nausea or vomiting, a seizure, slurred speech, weakness, numbness, or decreased coordination, unusual drowsiness or inability to wake up, increasing confusion, restlessness or agitation, one pupil larger than the other, double vision, not being able to recognize people or places, or loss of consciousness.¹

What Is a Concussion?

A concussion is a type of mild traumatic brain injury (mTBI). It can happen after a bump, blow, or jolt to the head, or after a hit to the body that makes the head and brain move quickly back and forth.¹ A direct blow to the head isn't required, and many people with a concussion never lose consciousness.¹

"Mild" describes how the injury is classified, not how it feels. Some people recover quickly, while others have symptoms for longer. Every person is different.

Symptoms People Commonly Report

Concussion symptoms are often grouped into four categories.¹ Not everyone has all of them, and many of these symptoms have other possible causes.

Physical

• Headaches
• Dizziness or balance problems
• Nausea
• Sensitivity to light or noise
• Vision problems
• Feeling tired, or having no energy

Thinking and memory

• Feeling foggy or groggy
• Feeling slowed down
• Trouble concentrating
• Trouble thinking clearly
• Problems with short- or long-term memory

Emotional

• Anxiety or nervousness
• Irritability or becoming easily angered
• Feeling more emotional
• Sadness

Sleep

• Sleeping more or less than usual
• Trouble falling asleep

When Symptoms Appear

Some symptoms may be noticed right away. Others may not be noticed for hours or days, especially once someone returns to work, screens, or busy settings.¹ Timing varies from person to person and doesn't by itself show whether, or how, someone was injured. Telling a provider what you notice, and when, helps them understand the full picture.

Concussion and Neck Symptoms Can Overlap

The same sudden motion that can cause a concussion can also strain the neck. Headaches, dizziness, and trouble concentrating can come from more than one source, so a provider looks at the whole picture. Learn more in our guide to whiplash after a rear-end crash.

What a Concussion Evaluation May Include

Evaluations vary by provider and patient. They commonly include:

• A history: what happened, what symptoms you've noticed and when, and any prior concussions, headaches, or other conditions.
• A neurological exam: for example, balance, coordination, eye movements, strength, reflexes, and sensation.
• Symptom checklists and cognitive testing: sometimes including computerized tests of memory, attention, and reaction time, when appropriate.
• Imaging only if indicated: standard CT and MRI scans are often normal with a concussion. CT is mainly used in emergency settings to check for bleeding when warning signs are present.¹

Our Concussion & TBI Evaluation page explains how evaluations work at our practice. When findings call for it, providers refer to neurology, emergency care, or other specialists.

General Tips While You Recover

General public-health guidance includes:¹

• Follow the advice of the provider who evaluated you.
• Take relative rest as advised, then return to activities gradually. Complete, prolonged rest is not the goal.
• Avoid activities that risk another head injury until a provider clears you.
• Don't drive if you feel drowsy, dizzy, or slowed down.

Frequently Asked Questions

Can you have a concussion without hitting your head? Yes. A hit to the body that makes the head move quickly back and forth can also cause a concussion.¹

Do you have to pass out to have a concussion? No. Many people with a concussion never lose consciousness.¹

Will a CT or MRI show a concussion? Often not. Standard brain imaging is frequently normal with a concussion. Imaging is mainly used to check for other problems, such as bleeding, when warning signs are present.¹

When should I go to the ER after a crash? Call 911 or go to the ER for a headache that gets worse and does not go away, repeated nausea or vomiting, a seizure, slurred speech, weakness, numbness, or decreased coordination, unusual drowsiness or inability to wake up, increasing confusion, restlessness or agitation, one pupil larger than the other or double vision, not being able to recognize people or places, or loss of consciousness.

Questions After a Crash in Bradenton or Riverview?

We see auto-injury patients at our Bradenton office (3633 Cortez Rd W, Ste A9) and our Riverview office (auto injury). Learn more about concussion & TBI evaluation, nerve testing (NCV/EMG), or our Riverview office.

📞 941-877-0317 · Request an appointment online

Se habla español en nuestra oficina de Bradenton.

Related reading: Whiplash After a Rear-End Crash · "Pinched Nerve" Pain That Travels · Patient Education

Sources

1. CDC HEADS UP, Signs and Symptoms of Concussion (updated September 15, 2025); and CDC, Symptoms of Mild TBI and Concussion (adult). Recovery guidance follows the CDC's current concussion recovery pages.

This article is for general educational purposes only and isn't medical or legal advice. It doesn't describe any particular patient or case, and it isn't an opinion about any individual. Reading it doesn't create a doctor–patient relationship. If you think you have a medical emergency, call 911 or go to the nearest emergency room.