Brain Injury After a Car Accident: What You Should Know

The Centers for Disease Control and Prevention (CDC) says a mild traumatic brain injury (TBI) or concussion can come from “a bump, blow, or jolt to the head.” It can also come from “a hit to the body that causes the head and brain to move quickly back and forth” (CDC). That movement can make the brain bounce or twist in the skull, stretch and damage brain cells, and cause chemical changes.

Crashes are a common cause. A CDC report on 2018 and 2019 data found that unintentional motor vehicle crashes accounted for about 17 percent of TBI-related deaths. That report counts an average of 10,291 of these deaths a year, with the highest rate among people ages 15 to 24 (CDC surveillance report).

A sudden jolt, like being rear-ended at a light, can whip the head back and forth even if it never strikes the wheel or window. The National Institute of Neurological Disorders and Stroke (NINDS) says bruises on the brain, called contusions, generally happen when the head abruptly decelerates, such as in a high-speed car crash. It adds that contusions can appear after a delay of hours to a day (NINDS).

That’s why “I didn’t hit my head” doesn’t rule out a brain injury, and why the first exam may not tell the whole story.

The CDC says some symptoms of a mild TBI may appear right away, “while others may not appear for hours or days after the injury” (CDC). A week or two later, a person may notice they feel more emotional than usual or have trouble sleeping.

NINDS also notes that some brain damage is secondary, meaning it can develop gradually over hours, days, or weeks after the injury. Our guide to traumatic brain injury symptoms lists what to watch for and the danger signs that need emergency care, such as a headache that gets worse and does not go away, or repeated vomiting.

The CDC says people with a mild TBI or concussion “need to be seen by a healthcare provider.” If you think you have a mild TBI or concussion, the CDC advises contacting your provider as soon as you can (CDC). Then:

• Tell the provider about the crash, including any jolt, dizziness, or confusion, even if you didn’t hit your head.
• Rest for the first day or two, then ease back into your usual activities and cut back if symptoms get worse, as the CDC suggests for a mild TBI or concussion. Ask for written instructions about returning to work, school, or driving.
• Talk with your provider again if symptoms don’t go away within 2 to 3 weeks or get worse after you return to your usual activities.
• Keep a simple log of symptoms, appointments, and missed work. It can help your doctors and any later claim.

The National Highway Traffic Safety Administration (NHTSA) says buckling up in a passenger car’s front seat can reduce the risk of fatal injury by 45 percent and moderate to critical injury by 50 percent (NHTSA). Air bags “reduce the chance that your upper body or head will strike the vehicle’s interior during a crash,” and they are designed to work with seat belts, not replace them (NHTSA).

Even with both, a hard stop can still move the brain inside the skull, so any new symptom after a crash is worth a medical check.

Under California law, damages for an injury caused by someone else’s negligence are generally the amount that will compensate for all the harm the negligence caused (Civ. Code §3333). In a brain injury case, that can include medical care now and later, lost income and earning capacity, and the effects on daily life. Because some symptoms appear late, the medical records from the first weeks matter.

If the at-fault driver has no insurance, uninsured motorist coverage on your policy, or on the car you were in, may help. If the driver’s liability limits are lower than that coverage, underinsured motorist coverage may help once the driver’s policy pays its limits (Ins. Code §11580.2). An injury lawsuit is generally due within two years (Code Civ. Proc. §335.1). A claim against a California public entity, such as a city, county, or the state, is generally due within six months (Gov. Code §911.2).

Our car crash brain injury results include:

• $7.1 million (2024, San Diego County): a crash with a pickup on a state highway left a driver hospitalized with a traumatic brain injury and other serious injuries.
• $2 million (2019, Long Beach): a three-car rear-end collision left an occupant with a traumatic brain injury and other serious injuries.

Past results do not guarantee a similar outcome. Every case is different.

• CDC, About Mild TBI and Concussion, Symptoms of Mild TBI and Concussion, What to Do After a Mild TBI or Concussion, and Surveillance Report of TBI-related Deaths, 2018–2019.
• National Institute of Neurological Disorders and Stroke, Traumatic Brain Injury.
• NHTSA, Seat Belts and Air Bags.

Wilshire Law Firm represents people with brain injuries from car crashes across California. Case reviews are free and available 24/7, and there are no fees unless you get paid.