This information reflects U.S. guidance; if you live elsewhere, follow local emergency guidance and check with a local pediatrician.
Why It Happens
A concussion happens when a bump, blow, or jolt to the head causes the head to move rapidly, making the brain bounce around or twist inside the skull. According to the CDC’s HEADS UP program, this rapid movement can create chemical changes in the brain and sometimes stretch or damage brain cells, even without any direct impact to the skull itself — a sudden acceleration or deceleration of the head can be enough on its own. CDC HEADS UP also identifies falls as the leading cause of traumatic brain injury and concussion in children, a pattern tied partly to how a young child’s head makes up a larger share of total body size and how balance and coordination are still developing.
How It Looks at Different Ages and Stages
HealthyChildren.org, from the American Academy of Pediatrics, notes that children under age 4 have the highest rates of concussion of any age group. Infants and toddlers can’t yet describe how they feel, so caregivers have to watch for changes in behavior, sleep, and feeding rather than relying on a symptom description. As children grow, the typical cause of head injury shifts: falls against furniture are more common in toddlers, while playground falls and sports-related impacts become more common once children reach school age.
Home Care After a Minor Bump
CDC HEADS UP guidance says a child who seems fine after a minor bump can sleep as usual; caregivers should check that the child is breathing normally, but there’s no need to wake them up repeatedly through the night. Recommendations have shifted away from strict, prolonged rest: CDC HEADS UP now advises one to two days of quiet rest followed by a gradual, symptom-limited return to light activity, while holding off on sports, biking, or other activities with a risk of another head impact until a healthcare provider says it’s okay. CDC HEADS UP also notes that most children recover from a concussion within 2 to 4 weeks.
Common Parent Misconceptions
A common misconception is that a child must lose consciousness to have a concussion. In reality, CDC HEADS UP lists loss of consciousness as just one of many possible signs, and most concussions happen without it — a dazed look, slowed responses, or confusion are far more typical. Another misconception is that a child who looks completely fine right after a bump is automatically in the clear; CDC HEADS UP notes that some symptoms may not appear for hours or even days afterward. A related myth is that a head-injured child should never be allowed to sleep — the real danger isn’t sleep itself, but mistaking a dangerously reduced level of consciousness for ordinary sleep, which is exactly why checking normal breathing matters more than keeping a child awake all night.
Signs That Need Emergency Care
CDC HEADS UP lists specific danger signs that call for 911 or an immediate emergency department visit: one pupil larger than the other, drowsiness or an inability to wake up, a headache that keeps getting worse, slurred speech, weakness, numbness, or decreased coordination, repeated vomiting, convulsions or seizures, any loss of consciousness, and increasing confusion, agitation, or unusual behavior. For infants who can’t describe symptoms, CDC HEADS UP adds specific warning signs: a bulging soft spot on the head, inconsolable crying, and refusing to nurse or eat. If any of these appear after a head bump, seek emergency care right away rather than waiting to see if they pass. This information isn’t a diagnostic tool and doesn’t replace advice from a medical professional.