When a Headache Is an Emergency

Call 911 for a sudden severe headache with no obvious cause, or a headache with confusion, slurred speech, weakness or numbness on one side, a stiff neck, or a high fever. A sudden, severe headache can be a stroke.

The test is not how much it hurts. Almost everybody assumes it is.

The American College of Emergency Physicians gives a different test, and it is the most useful sentence on this page:

“The nature, frequency or severity of the headache changes, or the pain feels different from pain associated with previous headaches.”

Different from your usual. Not worse necessarily — different. A new quality, a new pattern, a new speed of onset, a new place.

Which means the people best placed to spot a dangerous headache are the people who get them often — and, as below, the people most likely to talk themselves out of it.

Call 911

ACEP’s list, and any one of these with a headache is an emergency:

• High fever
• Confusion
• A stiff neck
• Prolonged vomiting
• Slurred speech
• Numbness or weakness — “especially on one side of the body”

And separately, the one that has its own reason:

“You experience a sudden, severe headache with no known cause, which may indicate stroke.”

Sudden and severe with nothing to explain it. ACEP flags it as a possible stroke sign, and notes it is not one of the traditional ones — so it does not appear on the posters. If a headache arrives at full force out of nowhere, that is a 911 call, and what to do in the first ten minutes of a stroke is the page for it.

Numbness or weakness on one side, slurred speech, and a headache together should be treated as a stroke until somebody with a scanner says otherwise.

The trap, and this page has to close it

If you get headaches, you already have an explanation for this one.

Migraine. Tension. Screens. Dehydration. Not enough sleep. Weather. Those explanations are usually right, which is exactly what makes them dangerous — a person with twenty years of migraines has twenty years of evidence that this will pass, and that evidence is why they wait.

So the rule is not “is this bad enough”. It is “is this mine”.

A headache that does not behave like yours do — different quality, different speed, different place, different company it keeps — has lost the benefit of your history. Your pattern is real data and it is the most valuable thing you have here. It stops being useful the moment the headache stops matching it.

Come in

ACEP names these as reasons to seek emergency care:

Medication is not touching it — “headache medication does not relieve chronic or excruciating pain.”

You cannot eat or drink — “head pain prevents eating or drinking, making one susceptible to dehydration or malnutrition.” Pain severe enough to stop you drinking is severe enough to be seen, and the dehydration becomes a second problem.

The medication itself is causing trouble — “major side effects to medication, such as severe drowsiness, sedation or nausea and vomiting.”

The pattern has changed — nature, frequency or severity.

Also come in for:

• A headache after any blow to the head, particularly with vomiting or drowsiness — see head injuries
• A headache that wakes you from sleep, or is worst first thing and then eases
• A headache made much worse by coughing, straining or bending forward
• A first severe headache in somebody over 50
• A headache with a new rash, especially small bleeding spots under the skin
• A headache in pregnancy, or in the weeks after giving birth
• A headache in anybody with a suppressed immune system, or a history of cancer
• The worst headache of your life — that phrase is worth saying at the desk in those words

Our emergency rooms are open every hour of every day and are walk-in, with CT in the building — which is the test most headache questions actually need. Go to the nearest one, and if another emergency department is closer, that one is the right answer tonight.

And ACEP’s own closing line applies: “Chronic or worsening headaches should be evaluated by a physician.” Our clinics are open Monday to Thursday and Friday mornings, with appointments by phone — that is the right setting for a pattern rather than an event.

If you are unsure, come in — this list is not exhaustive and you are not expected to tell your own migraine from something else.

Questions people actually ask

I get migraines. How do I know this is one? By whether it behaves like yours. Same warning signs, same build-up, same sort of pain, same duration — that is your migraine. Anything that breaks the pattern has lost the protection your history gives it.

It is the worst headache I have ever had. Be seen, and use those words. They are taken seriously for a reason.

It came on over a few hours and it is severe. Severity plus anything on the 911 list is a call. Severity alone, not settling, not responding to what normally works, is a reason to come in.

Is it my blood pressure? That is a common belief and not something to diagnose at home. If you have a headache and feel unwell, be seen rather than taking a reading and reasoning from it.

I have had a dull headache for three weeks. That is a clinic question rather than an emergency, and it is a real one — ACEP says chronic or worsening headaches should be evaluated. Make the appointment rather than waiting for it to become an emergency.

Caffeine, screens, dehydration — could it just be that? It could, and often is. What this page asks is a different question: is this headache like your others? If it is not, the cause list stops being useful.

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Sudden and severe with no cause, or with confusion, slurred speech, one-sided weakness, a stiff neck or a high fever — call 911. Both of our emergency rooms are open 24 hours a day, every day of the year, with CT on site — walk in, no appointment and no referral. Find your nearest emergency room →

Related reading: stroke — the first ten minutes · which door do you need

Sources

56. Headache — Know When To Go — American College of Emergency Physicians. https://www.emergencyphysicians.org/article/know-when-to-go/headache

This article is general information, not a diagnosis, and it cannot account for your history or your medications. It gives no doses. If you are unsure, come in — this list is not exhaustive and you are not expected to diagnose your own headache. If it might be an emergency, treat it as one and call 911.