How to Tell If My Toddler Has a Concussion

Toddler concussions show up primarily through behavior changes rather than the headache complaints or dizziness reports you would expect from an older child or adult. Because a one- or two-year-old cannot tell you their head hurts or that they feel foggy, you have to watch for indirect signals: sudden irritability, clingy comfort-seeking, disrupted sleep, and vomiting are among the most reliable clues. Research on early childhood concussion has expanded rapidly in recent years, and the picture it paints is that these injuries look quite different in toddlers than in school-age kids, which makes them easier to miss and harder to diagnose with certainty.

Why Toddler Concussions Look Different

A five-year-old who hits their head might say “my head hurts” or “things look blurry.” A toddler who hits their head screams, then acts weird for a while, and you’re left trying to figure out whether that weirdness is a concussion or just being a toddler. This is the core challenge. Standard concussion symptom checklists were developed for older children and adults who can self-report, and they rely heavily on subjective complaints like headache, feeling “in a fog,” difficulty concentrating, and sensitivity to light. Toddlers can’t articulate any of that.

Studies show that preschool-age children are less likely to present with classic concussion signs like loss of consciousness, drowsiness, or headache and more likely to present with irritability and agitation.¹ Symptom profiles genuinely shift by age, so using a checklist designed for a ten-year-old on your eighteen-month-old is going to miss things. Even validated concussion assessment tools perform poorly in this age group: cognitive screening and balance testing, the bread and butter of concussion evaluation in older kids, were essentially useless for distinguishing young concussed children from healthy ones in one outpatient study.²

The Behavioral Signs That Matter Most

If you take away one thing from this article, let it be this: irritability is the single most consistent sign of concussion in toddlers. In a large prospective study tracking children with early childhood concussion, irritability was the most frequently reported symptom at the emergency department visit, at ten days after injury, and at one month, with roughly three-quarters of concussed children showing it at each of those time points.³ That’s not garden-variety crankiness. Parents described a level of fussiness that stood out as unusual even for a toddler who had just experienced something scary.

Comfort-seeking was the second most common behavioral symptom, reported in about 70% of concussed toddlers both at the initial visit and ten days later.³ This looks like a child who won’t let go of you, who cries when put down, who wants to be held constantly in a way that feels different from their normal clinginess. Anxiety emerged as a prominent symptom at the one-month and three-month marks. Children under two years old were especially likely to show sleep disturbances and comfort-seeking behavior at every point measured after injury.⁴

What makes these signs tricky is that toddlers are irritable, clingy, and anxious on perfectly normal days. The key is the deviation from your child’s baseline. You know your toddler better than any doctor does. If their behavior has shifted sharply since a head bump, that shift itself is the symptom worth paying attention to, even if each individual behavior looks like something they’ve done before.

Physical Symptoms to Watch For

Behavioral changes are the headline, but physical symptoms still appear. In a review of clinical records, more than two-thirds of caregivers of children aged zero to four reported somatic symptoms such as vomiting and headache, and nearly half reported sleep problems.¹ Vomiting is one of the easier physical signs to catch because you don’t need a verbal report. A toddler who throws up once after a head injury might just have an upset stomach from crying, but repeated vomiting, or vomiting that starts more than an hour after the fall, is more concerning.

Sleep disruption can go in either direction. Some toddlers become unusually drowsy and hard to wake. Others have trouble falling asleep or wake up repeatedly through the night. Either pattern, if it appears after a head injury and is different from the child’s normal sleep, is worth noting. A child who suddenly fights bedtime or wakes screaming when they previously slept through the night has given you a data point.

Headache is harder to detect because toddlers can’t name it. Watch for head-holding, rubbing at the temples or forehead, wincing when moved, or refusing to look at bright lights. Parent-reported headache was actually one of the strongest discriminators between concussed young children and healthy ones in an outpatient assessment study, with excellent diagnostic performance when parents interpreted the nonverbal cues.² Fatigue, reported by parents as the child seeming excessively tired or tiring out faster than usual, was another strong signal in that same research.

A Practical Checklist

After a head injury, watch for these changes in the hours and days that follow. Not every concussed toddler will show all of them, but a cluster of several appearing together, especially when they represent a shift from your child’s normal patterns, is a reason to seek medical evaluation.

• Irritability: Crying that is harder to soothe than usual, fussiness that seems disproportionate, tantrums that are longer or more intense.
• Clinginess: Wanting to be held constantly, distress when put down, following you more closely than normal.
• Sleep changes: Unusual drowsiness, difficulty waking, new trouble falling asleep, or waking repeatedly at night.
• Vomiting: Especially if it happens more than once or begins well after the initial injury.
• Headache signs: Grabbing or rubbing the head, wincing at movement or bright light, refusing to look upward.
• Loss of interest: Not wanting to play with toys, eat, or engage in activities they normally enjoy.
• Balance problems: Wobblier than usual, falling more, seeming uncoordinated even by toddler standards.
• New anxiety: Fear of activities or situations that didn’t bother them before.

When to Go to the Emergency Room

Some signs after a head injury demand immediate medical attention, not a wait-and-see approach. Go to the emergency room if your toddler loses consciousness, even briefly. Go if they have a seizure. Go if you notice clear fluid draining from the nose or ears, if there is significant swelling at the injury site (especially if it’s not on the forehead), or if the child seems progressively less alert over the hours after the fall. Persistent vomiting, inability to wake the child from sleep, or one pupil looking larger than the other are all emergency-level signals.

Emergency departments use clinical decision rules to help determine whether a young child needs a CT scan after head trauma. The PECARN prediction rule is the most widely used. In a study of infants younger than three months, the rule had perfect sensitivity for identifying clinically important traumatic brain injuries; no child who met the low-risk criteria had a significant brain injury.⁵ For toddlers, the rule considers factors like how the child is acting (normal behavior vs. altered mental status), whether there is vomiting, the mechanism of injury, and whether there is a scalp hematoma that is not on the forehead. If the doctor says a CT scan isn’t needed based on these criteria, that is generally a safe and evidence-based call, even though it might feel unsettling to leave without imaging.

The Typical Recovery Timeline

Most toddler concussions resolve without lasting problems, but the timeline is not as fast as some parents expect. In the study tracking postconcussive symptoms over three months, children with concussion showed a clear pattern: behavioral and cognitive symptoms peaked at about ten days after injury and then gradually improved, while physical symptoms like vomiting peaked at the initial emergency visit and declined from there.⁶ At three months, concussed children still had significantly more symptoms than both uninjured children and children who had sustained other types of injuries, though the gap was narrowing.

Symptoms typically resolve within weeks, but both children and adults can experience postconcussive problems for months or longer.⁷ For a toddler, that might mean several weeks of being more irritable than usual, sleeping differently, or seeming off. It doesn’t mean something has gone permanently wrong. But if symptoms persist or worsen beyond a few weeks, a follow-up with a pediatrician or pediatric neuropsychologist is warranted.

One particularly frustrating piece of the puzzle is that current return-to-activity guidelines are designed for school-age children and offer little guidance for toddlers. Caregivers in one qualitative study reported that the educational pamphlets they received contained only broad information about possible symptoms and had no specific recommendations for when their young child could return to daycare or normal physical play.⁸ In practice, the general principle is a gradual return: start with quiet play, then reintroduce normal activity as tolerated, and pull back if symptoms flare. If your child seems worse after running around or being in a stimulating environment, they need more rest.

What Causes Toddler Concussions in the First Place

Falls are overwhelmingly the leading cause. In a Canadian study of nearly 80,000 mild traumatic brain injuries in children five and under, falls accounted for about 85% of cases.⁹ The prevalence of falls was significantly higher in infants and toddlers compared to preschoolers, with toddlers roughly 17% more likely to have a fall-related injury. Beds were the single most common piece of furniture involved, with falls from beds occurring about 1.3 times more often in toddlers than in older preschoolers. Floors were the most common surface landed on.

A U.S. study confirmed that furniture, especially beds, ranked high across all age groups, while stairs and household structures like bathtubs and doors became more prominent injury sources for children aged two to four.¹⁰ Younger children under one year had the highest rate of head-specific injuries from falls, including skull fractures, because their body proportions make them more likely to land head-first.¹¹

There’s an interesting biomechanical wrinkle here. Toddler heads experience higher accelerations than infant heads during falls from the same height onto the same surface, likely because of differences in body mass and stiffness. However, the thicker toddler skull actually makes skull fracture less likely than in infants, even though the forces involved are greater.¹² The takeaway for parents is that even short falls, like rolling off a bed or tumbling down a few stairs, can produce enough force to cause a concussion in a toddler, even if the skull isn’t fractured.

Practical Steps to Reduce the Risk

Since beds are the most commonly implicated piece of furniture, the simplest intervention is keeping toddlers off elevated sleeping surfaces or using bed rails. If your toddler has transitioned out of a crib, putting their mattress on the floor for a while eliminates the bed-fall risk entirely. Stair gates remain important well into the toddler years. Securing furniture that can be climbed (bookshelves, dressers) and padding hard floor surfaces in play areas are sensible steps. None of this eliminates risk completely, since toddlers are in the business of finding new ways to fall, but it addresses the most common scenarios.

Being struck by or against an object accounted for about 13% of early childhood head injuries in the Canadian data, covering things like walking into a table corner, being hit by a thrown toy, or running into another child.⁹ Corner guards on sharp furniture edges and supervising play with heavier or harder toys can help with that category.

What About Second Impacts

One reason to take even a mild concussion seriously is the risk that comes with a second head injury before the first has fully healed. Second impact syndrome is rare but devastating: diffuse brain swelling, herniation, and death can occur within minutes when someone sustains another head injury while still recovering from a concussion.¹³ Most of the documented cases involve adolescent athletes, not toddlers, but the underlying biology applies at any age. This is why the rest-and-gradual-return approach matters: a toddler who is still symptomatic should not be thrown back into rough play or situations where another head bump is likely.

The Long-Term Picture

Most toddlers recover fully from a single concussion without detectable long-term problems. But the evidence is not entirely reassuring for every case. One study found that children with mild traumatic brain injuries were at risk of longer-term deficits in cognitive and behavioral functioning, with evidence suggesting shortfalls in school performance extending up to two years after the injury.¹⁴ A toddler’s brain is still developing rapidly, and an injury during this period could theoretically disrupt developmental trajectories in ways that don’t become apparent until the child reaches school age and faces more demanding cognitive tasks.

This does not mean a single fall from the couch will cause learning disabilities. The risk is modest, and many factors influence whether a concussion has lasting effects, including the severity of the initial injury, whether the child had prior head injuries, and how the recovery period was managed. What the research suggests is that even mild brain injuries in early childhood deserve follow-up attention. If your toddler has a concussion, it’s worth mentioning it at future well-child visits and keeping an eye on developmental milestones in the months and years that follow.

Blood Biomarkers and the Future of Diagnosis

The difficulty of diagnosing concussions in toddlers has pushed researchers toward blood-based tests that could provide objective evidence of brain injury. Two proteins, GFAP and UCH-L1, have shown the most promise. GFAP is released when a specific type of brain cell is damaged, while UCH-L1 comes from injured neurons. A blood test measuring both was approved by the FDA for adults in 2018 and has been studied in children as well.

In children, GFAP levels drawn within twenty-four hours of injury were able to distinguish concussed patients from those with body injuries but no brain involvement with reasonable accuracy.¹⁵ For detecting actual structural injuries visible on CT, GFAP performed even better in children under five than in older kids, with near-perfect performance in one analysis.¹⁶

There is a catch. Normal GFAP levels appear to vary by age in children, with younger children having different baseline levels than older ones. Diagnostic cutoffs designed for adults or older children may need adjustment for kids under eleven.¹⁷ These tests are not yet standard practice in pediatric emergency rooms for toddler concussions, but they represent the direction the field is moving. For now, the diagnosis still rests primarily on what you, the caregiver, observe and report.

The Emotional Toll on Caregivers

Research on early childhood concussion has increasingly recognized that the parent’s experience matters for recovery, not just as an emotional reality but as a clinical one. A parent’s mental state, stress level, and parenting approach after a child’s concussion can influence the trajectory of recovery.¹⁸ Anxious parents may inadvertently restrict their child’s activity too aggressively or overinterpret normal toddler behavior as symptoms, both of which can prolong the recovery process.

If your toddler has a concussion, it’s worth being honest about your own anxiety. A certain amount is healthy and keeps you vigilant. But if you find yourself unable to let the child play normally weeks after the injury, or you’re checking on them every hour during the night long after the danger window has passed, it may help to talk to your own doctor or a therapist. Your calm confidence helps your child recover. The research is clear that family functioning is one of the strongest predictors of how well a young child bounces back from a mild brain injury.