When to Go to the Emergency Room for a Head Injury

If someone has hit their head and is having a seizure, cannot be woken, does not recognise people or places, or has one pupil larger than the other, call 911 now.

The head injury that needs an emergency room is not always the one that looked worst when it happened. A hard fall with an immediate headache can turn out to be nothing much. A knock that seemed minor, followed three hours later by worsening headache and repeated vomiting, is the one that matters.

Which is why the useful question is not how bad was the impact but what has happened since.

The danger signs, as the CDC lists them

The Centers for Disease Control and Prevention says to call 911 or go to your nearest emergency department if you notice any of these after a bump, blow or jolt to the head:

• Convulsions or seizures — shaking or twitching
• Not able to recognise people or places
• Repeated nausea or vomiting
• Unusual behaviour, increased confusion, restlessness or agitation
• Loss of consciousness with increasing drowsiness, an inability to wake up, or an inability to stay awake
• Slurred speech, weakness, numbness, or decreased coordination
• A headache that gets worse and does not go away
• One pupil larger than the other, or double vision

In infants and toddlers, add two more: a child who will not stop crying and cannot be consoled, and a child who will not nurse or eat.

Any single one of those is enough. You are not waiting for a set.

The two signs people most often talk themselves out of

“A headache that gets worse and does not go away.” Almost every head injury produces a headache, so a headache on its own is not the signal. The signal is the direction. A headache that was a four and is now a seven, two hours later, is telling you something a headache that has stayed a four is not.

“One pupil larger than the other.” Nobody thinks to look, and it is the sign most likely to be missed in a household where somebody has been sent to bed to sleep it off. It is worth looking.

Concussion signs that are not danger signs — and still deserve a call

The CDC separately lists the general signs of a concussion, and a concussion is a brain injury even when none of the danger signs above appear:

Physical — headaches, nausea or vomiting, dizziness, balance problems, vision problems, sensitivity to light or noise, fatigue. Thinking and remembering — difficulty thinking clearly, feeling slowed down or foggy, problems with attention or concentration, memory problems. Mood — irritability, anxiety, sadness, more emotional than usual. Sleep — sleeping more or less than usual, or trouble falling asleep.

These are worth being seen for, and the reason is practical rather than dramatic: what a person does in the days after a concussion changes how long it takes to resolve, and that guidance is specific to the person.

If you are unsure, come in — this list is not exhaustive and you are not expected to assess a brain injury yourself.

The things that raise the stakes

Some circumstances make a head injury more serious than the same knock would otherwise be, and they are worth saying out loud when you arrive:

Blood thinners. Anticoagulants are the single most important thing to mention. A bleed that would have stopped on its own may not.

Age. Older adults bleed more easily inside the skull and can do so after a fall that seems unremarkable.

Alcohol. It makes the assessment harder, because drowsiness and confusion have two possible explanations and only one of them is safe to assume.

A fall from height, being thrown, or any impact you cannot fully account for. The National Library of Medicine’s guidance on recognising medical emergencies puts severe injuries — including those where moving the person could worsen the damage — in the call-911 category outright.

And do not move someone with a suspected neck or spine injury. Call.

What happens when you come in

Expect questions about the mechanism — how it happened, from what height, whether there was any loss of consciousness, what has changed since — and a neurological examination.

Whether you need a CT is a clinical judgement based on those answers and not on how sore your head is. Both of our emergency rooms have CT in the building, staffed around the clock, so where a scan is the right call it happens during the visit rather than being scheduled for another day. That is the whole reason an emergency room is the right door for this: the question “is there a bleed” cannot be answered by examination alone, and it cannot usefully wait.

Our emergency rooms are freestanding, and a head injury that turns out to need neurosurgical care needs a hospital. We assess, image and stabilise, and arrange the transfer. In a head bleed that is the point — being scanned quickly at the nearest door, then moved to the right bed.

Questions people actually ask

They did not lose consciousness. Is it still worth coming? Yes. Most concussions happen without any loss of consciousness, and the danger signs above do not require it either.

Should I keep them awake? That old advice has been superseded — sleep itself is not the danger. What matters is whether they can be roused normally. An inability to wake up, or increasing drowsiness, is a 911 sign.

It has been a day and now the headache is worse. That is exactly the pattern to act on. Come in.

Can they go back to sport this week? That is a decision for whoever assesses them, based on symptoms rather than on a fixed number of days. It is one of the practical reasons to be seen.

They are on a blood thinner but seem completely fine. Say so when you arrive, and come in. That combination is the one where “seems fine” carries the least weight.

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For any of the danger signs above, call 911 or go to the nearest emergency room. Both of ours are open 24 hours a day, every day of the year — walk in, no appointment and no referral, with CT and a full laboratory in the building. Find your nearest emergency room →

Related reading: which door do you need · what our emergency rooms can do

Sources

3. Recognizing medical emergencies — MedlinePlus Medical Encyclopedia, U.S. National Library of Medicine. https://medlineplus.gov/ency/article/001927.htm
10. Signs and Symptoms of Concussion — HEADS UP, Centers for Disease Control and Prevention. https://www.cdc.gov/heads-up/signs-symptoms/index.html

This article is general information, not a diagnosis, and it cannot account for someone’s history or medications. If you are unsure, come in — this list is not exhaustive and you are not expected to diagnose yourself. If it might be an emergency, treat it as one and call 911.