Most traumatic brain injuries in the United States come from a short list of causes: falls, motor vehicle crashes, being struck by or against an object, assaults, and sports injuries. The CDC’s surveillance data shows falls far ahead of the rest — accounting for nearly half of all TBI-related hospitalizations — with the ranking shifting by age group.
Falls: the leading cause
Falls cause more traumatic brain injuries than anything else in the United States. The CDC reports that falls lead to nearly half of all TBI-related hospitalizations, and they strike hardest at the two ends of the age spectrum: young children and older adults. For the newest figures, see our 2026 brain injury statistics roundup.
For older adults, the risk is compounded by frailty, balance problems, vision changes, and medications — including blood thinners, which the CDC notes can increase the risk of bleeding in the brain after a TBI. A fall that a younger person walks away from can hospitalize an older adult. The CDC specifically advises that older adults who have fallen or been in a crash be checked for TBI signs, because symptoms are easily missed or mistaken for other conditions common at that age.
For young children, falls from furniture, stairs, playground equipment, and being dropped are the typical scenarios. Because small children cannot describe symptoms, caregivers must watch behavior instead — a topic covered in our symptoms checklist.
Fall-related brain injuries often become premises-liability or workplace claims: a wet supermarket floor with no warning sign, a broken stair railing, an unguarded loading dock. In those cases, evidence of the hazardous condition — photos taken promptly, incident reports, maintenance records — is as important as the medical evidence.
Motor vehicle crashes
Vehicle-related collisions — cars, motorcycles, bicycles, and pedestrians struck by vehicles — are the next major cause. The NINDS lists vehicle-related injuries as the third most common cause of TBI overall, and the CDC counts motor vehicle crashes among the most common ways people sustain TBIs.
Crashes are especially dangerous for the brain because of the physics involved: sudden deceleration whips the brain against the skull (producing contusions, often on the side opposite the impact) and rotational forces shear nerve fibers throughout (diffuse axonal injury). Occupants can sustain a TBI without the head striking anything — the jolt alone is enough.
Crash-related brain injury claims are typically third-party claims against the at-fault driver’s liability insurance, sometimes supplemented by the injured person’s own uninsured/underinsured motorist coverage. Police reports, vehicle damage photos, and event data recorder information all help reconstruct what happened. Our guide to brain injury car accident claims goes deeper on this claim type.
Struck by or against an object
This broad category covers being hit by a falling object, walking into or against a structure, and being struck during work or play. It is a leading cause of TBI-related emergency visits, particularly among older children and teens, and it dominates certain settings:
- Construction and industrial sites, where falling tools, materials, and equipment are constant hazards. These cases often involve both workers’ compensation and potential third-party claims.
- Workplaces generally, from warehouse shelving collapses to falling inventory in retail stockrooms — see brain injury workplace claims.
- Recreational settings, where playground equipment, falling branches, or sports equipment cause head strikes.
Hard hats and helmets exist precisely because this category is so preventable. When protective equipment was required but absent, or was provided but defective, that fact becomes central to the claim.
Assaults and violence
The CDC lists assaults among the most common ways people get TBIs. This category includes physical assaults, intimate partner violence, child abuse (including shaken baby syndrome), and gunshot wounds to the head. NINDS groups these under assaults and violence, noting they include abuse-related injuries and wounds from gunshots or other weapons.
These cases carry complications beyond the medical ones. Victims may be reluctant to report, injuries may be misattributed, and the at-fault party may lack insurance — which shifts the focus to victims’ compensation programs, the victim’s own coverage, or premises-security claims where an assault was foreseeable and preventable. Documentation is especially delicate here and should be guided by victim advocates and counsel, not improvised.
It is worth stating plainly: if you or someone you love is experiencing violence, safety comes before any claim. Medical care, a safe place, and a victim advocate are the first calls.
Sports and recreation
Contact and collision sports — football, soccer, hockey, boxing, lacrosse — along with cycling, skateboarding, skiing, snowboarding, and horseback riding, produce a steady share of TBIs, concentrated among young athletes. The Mayo Clinic lists sports injuries among the common causes of TBI and notes they are particularly common in youth.
The defining issue in sports TBIs is the second impact: returning to play before a concussion has healed, which can turn a recoverable injury into a catastrophic one. This is why every state now has some form of youth concussion law requiring removal from play and medical clearance before return — the subject of our article on youth sports concussion rules. Claims in this space often turn on whether coaches, schools, or leagues followed their own concussion protocols.
Blast and military injuries
Explosive blasts are a signature cause of TBI among active-duty service members — NINDS notes that blast trauma from roadside bombs has become a common injury in military conflicts, and that the majority of these TBIs are classified as mild. The mechanism is unusual: the pressure wave itself disrupts brain function even without a direct blow, and blast victims often sustain combined injuries — the wave plus shrapnel, falls, or vehicle collisions in the same event.
These injuries are typically handled through military and veterans’ systems rather than civilian claims, but they matter to families navigating the VA process, where documenting the exposure history is its own challenge.
Who is most at risk
Brain injuries do not distribute evenly. The Mayo Clinic identifies the highest-risk groups as newborns to age 4, young adults ages 15 to 24, adults 60 and older, and males in every age group. The CDC and BIAA add service members and veterans, people in rural areas, survivors of intimate partner violence, and people experiencing homelessness to the elevated-risk list.
Each group faces a different dominant cause: falls for the very young and the elderly, vehicle crashes for teens and young adults, blast injuries for service members. Prevention follows the same pattern — it is age-specific. Child safety seats and stair gates for toddlers, seatbelts and sober driving for teens, fall-proofing and vision checks for older adults, helmets for cyclists and athletes of all ages. The NINDS prevention guidance centers on exactly these habits: seatbelts, helmets, sober driving, and home fall-proofing.
Risk awareness also matters after an injury. Older adults on blood thinners, children too young to describe symptoms, and anyone with a prior TBI all warrant a lower threshold for evaluation — when in doubt, get checked.
How the cause shapes the claim
The cause of the injury does not change the medicine, but it changes nearly everything about the claim:
- Who pays. A crash points to auto liability insurance; a workplace fall to workers’ compensation (and possibly a third party); a defective helmet to a product-liability claim; an assault to victims’ compensation funds.
- What must be proven. A crash claim needs fault — who ran the light. A premises claim needs notice — the owner knew or should have known about the hazard. A product claim needs a defect. Each theory demands different evidence, gathered early.
- Which deadlines apply. Different claim types can carry different filing deadlines and notice requirements, which is why identifying the right path in the first weeks matters.
Whatever the cause, the first steps are the same: medical care, then documentation. The first-72-hours guide lays out exactly what to do and in what order.
Key takeaways
– Falls are the leading cause of TBI in the US — nearly half of TBI-related hospitalizations — hitting young children and older adults hardest.
– Motor vehicle crashes are the next major cause, and their physics (deceleration plus rotation) produce some of the most severe injury patterns.
– Struck-by incidents, assaults, sports injuries, and blast exposures round out the leading causes, each concentrated in different populations.
– The CDC and NINDS agree on the ranking; the order shifts with age, which is why prevention advice is age-specific.
– The cause determines who pays, what must be proven, and which deadlines apply — so identifying the right claim path early matters.
Frequently asked questions
What is the number one cause of traumatic brain injury?
Falls. The CDC reports that falls lead to nearly half of TBI-related hospitalizations in the United States, more than any other cause.
Are car accidents a common cause of brain injury?
Yes. The CDC lists motor vehicle crashes among the most common ways people sustain TBIs, and NINDS ranks vehicle-related injuries as the third most common cause overall.
Can a brain injury happen without a direct hit to the head?
Absolutely. Blast pressure waves, violent shaking, and the whiplash forces of a crash can all injure the brain without anything striking the head.
Which age groups are at highest risk?
The Mayo Clinic identifies newborns to age 4, young adults 15 to 24, adults 60 and older, and males in every age group as the highest-risk populations.
Can one incident involve more than one cause category?
Yes, and it happens often. A crash victim can be both struck by vehicle forces and thrown against an object; a blast victim can suffer the pressure wave plus shrapnel plus a fall. Each mechanism can produce a different injury pattern, which is worth making sure the medical records reflect.
This article is general information, not legal or medical advice. It does not create an attorney-client relationship. Consult a qualified attorney about your situation, and see a doctor promptly for any head injury.