# Traumatic brain injury and concussion after a car accident

> How crashes cause concussions and other brain injuries, symptoms that can be missed, why scans can look normal and how a brain injury claim is documented.

Canonical page: https://accidentclaimfacts.com/injuries/traumatic-brain-injury/  
Last reviewed: October 29, 2026 by the Accident Claim Facts editorial team  
General information, not legal advice. Talk to a licensed attorney in your state.

## Quick answer

A traumatic brain injury (TBI) is damage to the brain caused by an outside force, such as the jolt of a crash; a concussion is a mild form. Motor vehicle crashes caused 23.8% of nonfatal TBI hospital stays in 2018, second only to falls. Because some symptoms appear hours or days later and scans can look normal after a mild injury, a brain injury claim depends on early care, specialist testing and records that show how daily life has changed.

## Key facts

| Fact | Detail | Note |
|---|---|---|
| TBI-related deaths in the US | More than 69,000 | CDC, 2021 |
| Nonfatal TBI hospital stays | 223,050 | CDC, 2018 |
| Share caused by motor vehicle crashes | 23.8% | Second only to falls (51.0%) |
| When some concussion symptoms appear | They may not appear for hours or days after the injury | CDC |
| Time a provider has to answer a records request | 30 days | HIPAA right of access |

## What TBI and concussion are

The National Institute of Neurological Disorders and Stroke (NINDS) defines a traumatic brain injury as a brain injury caused by an outside force. A forceful bump, blow or jolt to the head or body can cause one, although not every blow or jolt does. The head does not have to strike anything: a concussion can come from a rapid movement of the brain inside the skull.

NINDS describes closed head injuries, also called non-penetrating TBI, as caused by a force strong enough to move the brain within the skull, and lists motor vehicle crashes among their causes. One of the most common types, diffuse axonal injury, is widespread damage to the brain's white matter that commonly happens in auto accidents.

Brain injuries range widely. NINDS says some cause temporary problems with how a person thinks, understands, moves, communicates and acts, while more serious ones can lead to severe and permanent disability. A concussion is a type of mild TBI, but "mild" describes the injury at the start, not necessarily its effects: NINDS notes that post-concussion syndrome involves symptoms that last for weeks or longer.

## How often crashes cause brain injuries

The CDC says people most commonly get a TBI from a fall, firearm-related injury, motor vehicle crash, or an assault. Crashes are a major source of the brain injuries that put people in the hospital. Of the 223,050 nonfatal TBI hospital stays in 2018, motor vehicle crashes caused 23.8%, behind only unintentional falls at 51.0%.

Brain injuries can also be fatal: the CDC counted more than 69,000 TBI-related deaths in 2021, from all causes.

## Symptoms that can be missed

According to NINDS, headache, dizziness, confusion and fatigue tend to start right after the injury, while emotional symptoms such as frustration and irritability tend to develop during recovery. Other symptoms NINDS lists include:

- problems remembering, concentrating or making decisions;
- changes in sleep, such as sleeping more or having trouble falling asleep;
- blurred vision, ringing in the ears, or sensitivity to light or sound;
- mood changes, anxiety or depression, and a lack of energy or motivation.

Several things make these easy to miss after a crash. The CDC says some concussion symptoms may not appear for hours or days after the injury. NINDS explains that bruising of the brain can appear after a delay of hours to a day, and that some damage develops over hours or days after the first injury. And many of these symptoms, such as poor sleep or irritability, are easy to put down to stress.

> **Warning:** The CDC says anyone who has had a bump, blow or jolt and then has a headache that gets worse and does not go away, weakness or numbness, repeated vomiting, slurred speech, one pupil larger than the other, confusion, or is very drowsy or cannot be woken needs emergency care right away. Call 911 or go to an emergency room.

> **Example:** A passenger in a side-impact crash is checked for cuts at the emergency room and goes home. A week later, back at work, she keeps losing track of tasks and gets headaches under bright office lights. She sees her doctor and explains the crash and when the problems began, and her doctor refers her for further evaluation. Those notes link the new symptoms to the crash.

## How a brain injury is documented

NINDS says every TBI should be evaluated right away by a professional experienced with these injuries. The record that follows usually includes:

- **A neurological exam,** which checks movement and sensation, hearing and speech, coordination and balance, mental status, and changes in mood or behavior.
- **Imaging.** NINDS says a CT scan can show a skull fracture and bruising, bleeding or swelling of the brain, while an MRI is more sensitive and can pick up subtler changes a CT scan may miss.
- **Neuropsychological testing.** These are tasks that measure memory, concentration, information processing, executive functioning, reaction time and problem solving. NINDS says they are often used along with imaging after a mild TBI.

The limits of scans matter for a claim. NINDS states that today's clinically validated imaging, blood tests and other measures cannot always detect damage from mild, concussive injuries. A normal CT scan can rule out some dangers, such as bleeding, without showing that the brain was not injured.

An adjuster may still point to a normal scan as a sign that there was no injury. Testing results, consistent notes from treating doctors and before-and-after evidence from work and home can answer that argument. Our guide to [medical records for an injury claim](https://accidentclaimfacts.com/claim-process/medical-records/) explains how to request every record.

## Effects on work and daily life

The symptoms NINDS describes, such as trouble concentrating, fatigue and sensitivity to light, can show up clearly at work. NINDS also says people should return to daily activities gradually, and only once a doctor allows it.

In a claim, these effects can appear in several ways:

| Effect | Where it can show up in a claim |
|---|---|
| Time off work or reduced hours | Lost wages, backed by pay records and an employer's letter |
| Unable to return to the same job | Lost earning capacity, usually with expert evidence |
| Trouble with reading, driving or screens | Effects on daily life described in a journal and by family |
| Mood changes and strained relationships | Pain and suffering, and possibly a family member's own claim |

For a lasting loss of earning capacity, courts compare what the person could have earned with what they can earn now. California's jury instruction, for example, tells jurors to compare what the injured person could probably have earned without the injury with what they can still earn with it. Our guide to [lost wages](https://accidentclaimfacts.com/money/lost-wages/) covers both kinds of loss.

Performance reviews, emails and statements from coworkers from before and after the crash can show a change that a single doctor's visit cannot.

## The role of family members

Family members may notice changes the injured person does not: a shorter temper, forgotten conversations, new trouble with routines. Many people find it useful for a spouse, parent or close friend to keep a short, dated log of what they see and to share it with the treating doctors. NINDS points out that children may be unable to say that they feel different after a blow to the head, so adults need to watch their behavior.

In a claim, family members can give statements that describe the person before and after the crash. That evidence can carry weight because it comes from people who saw daily life up close.

A spouse may also have a claim of their own. A loss of consortium claim covers the harm to the relationship. In California, for example, it covers the loss of the injured spouse's love, companionship, comfort, care, assistance, protection, affection, society, and moral support. Who can bring such a claim, and what it covers, varies by state.

## How insurers approach brain injury claims

Brain injury claims are often disputed. An insurer may point to a normal scan, a delay before diagnosis, an earlier concussion or sports injury, or other explanations such as stress or depression. It may ask for an independent medical exam or testing by a neuropsychologist it chooses.

These claims also take time. It can be a while before doctors can describe the long-term effects, so many claims are not ready to value until the person reaches maximum medical improvement. Your state's filing deadline keeps running in the meantime. If symptoms involve anxiety or flashbacks after the crash, see our guide to [PTSD after a car accident](https://accidentclaimfacts.com/injuries/ptsd-after-a-car-accident/).

## FAQ

### Can you get a concussion in a car accident without hitting your head?

Yes. NINDS says a forceful jolt to the head or body can cause a brain injury, and a concussion can result from a rapid movement of the brain inside the skull, without the head striking anything.

### How long after a car accident can concussion symptoms appear?

The CDC says some concussion symptoms appear right away, while others may not appear for hours or days. Emotional symptoms such as irritability tend to develop during recovery, according to NINDS.

### My CT scan was normal. Can I still have a brain injury?

It is possible. NINDS says current imaging and blood tests cannot always detect damage from mild, concussive injuries. A doctor decides which other evaluations, such as an MRI or neuropsychological testing, are appropriate.

### What is neuropsychological testing?

It is a set of tasks that measure memory, concentration, information processing, executive functioning, reaction time and problem solving. NINDS says these tests are often used along with imaging after a mild brain injury.

### Can my spouse make a claim because of my brain injury?

In many states, a spouse can bring a loss of consortium claim for the harm to the relationship, such as the loss of companionship and support. The rules on who can claim and what is covered vary by state.

### How can I show that a brain injury affected my work?

Pay records, an employer's letter, performance reviews and coworkers' statements from before and after the crash can show the change. For a lasting loss, experts often compare what you could have earned with what you can earn now.

## Sources

- [National Institute of Neurological Disorders and Stroke, Traumatic Brain Injury (TBI)](https://www.ninds.nih.gov/health-information/disorders/traumatic-brain-injury-tbi) — definitions, symptoms, diagnosis, imaging limits, neuropsychological tests
- [CDC, Traumatic Brain Injury & Concussion: Signs and Symptoms](https://www.cdc.gov/traumatic-brain-injury/signs-symptoms/index.html) — danger signs and symptom timing
- [CDC, MMWR 70(48): Incidence of Nonfatal Traumatic Brain Injury-Related Hospitalizations, United States, 2018](https://www.cdc.gov/mmwr/volumes/70/wr/mm7048a3.htm), checked October 29, 2026
- [CDC, Traumatic Brain Injury & Concussion: Facts and Stats](https://www.cdc.gov/traumatic-brain-injury/data-research/facts-stats/index.html), checked October 29, 2026
- [Judicial Council of California, Civil Jury Instructions (CACI) 2026 edition, No. 3903D](https://courts.ca.gov/system/files/file/judicial_council_of_california_civil_jury_instructions_2026.pdf), checked October 29, 2026
- [HHS, HIPAA FAQ: How timely must a covered entity be in responding to individuals' requests for access to their PHI?](https://www.hhs.gov/hipaa/for-professionals/faq/how-timely-must-a-covered-entity-be/index.html), checked June 24, 2016