What is a thunderclap headache and when

Now I'll write the family-facing draft and run it through the gate.

Call your local emergency number now and ask for an ambulance.

Say this to the dispatcher, word for word: "Sudden worst-ever headache, at full strength within seconds, started at [time]." If you are unsure of the time, give the closest you can and say what they were doing when it hit.

I am not a doctor and cannot diagnose this from home, so I will not guess at the cause. What I can do is tell you why this pattern is treated as an emergency, what to do in the next few minutes, and how to hand the rest of the family over so you are not carrying this alone.

What a thunderclap headache is

A thunderclap headache goes from nothing to the worst pain of their life in seconds, instead of building up over hours like most headaches. That pattern matters because the kind of brain injury it can signal can become irreversible within minutes to a few hours — so the window is now, not after sleep.

Three things families usually get wrong:

• The neck is usually not stiff at the start. A supple neck is not reassurance, and it is not a reason to wait.
• Collapse, vomiting, confusion, restlessness or a fit can follow — sometimes not for hours. Someone who already gets migraines can still have this.
• It can happen with no other symptom at first. There is no home test that separates this from a bad migraine, which is exactly why it is judged by the pattern and not by how the person looks.

1. What you already tried, and what works better

2. What to avoid

• Do not stay at home waiting to find out whether it settles.
• Do not give aspirin, and do not start, stop or change any medicine they already take.
• Do not drive them yourself; send an ambulance.
• Do not give food, drink or tablets if they are drowsy, confused or hard to wake.
• Do not put anything in the mouth during a fit, and do not hold their limbs down. Move hard objects out of the way and let the fit run.
• Do not leave them alone while you are on the phone with the crew.

3. Decision tree — go now, or stop home care

Go now, without waiting for the next step:

• The headache peaked within seconds, or is the worst they have ever had. You are here now.
• One side is weak or numb, speech is slurred or lost, or vision changed.
• Repeated vomiting, confusion, unusual drowsiness, restlessness, or a fit.
• Fever with a stiff neck, or a headache after a knock to the head.
• A new headache in someone over 50, with jaw pain on chewing, a tender temple, or flickering vision.
• A severe headache with blurred or flashing vision during pregnancy or in the days after birth.

If any of these appear after you have called, tell the dispatcher, and if the crew has not arrived, call again. If the pain eases before the ambulance arrives, that does not cancel the journey — they still need to be seen today.

While you wait or travel — the next few minutes

• Write down the exact time it started, and what they were doing.
• Dim the lights, turn the noise down, keep the room calm.
• Let them choose the position they want, and keep them comfortable and still.
• Gather their medicines, their allergies and any recent hospital letters, and put them in a bag.
• If they vomit, keep them sitting up and note it.
• Nothing by mouth if they are not fully awake.

What to tell the crew

Their age, then: when it started and whether it peaked within seconds; where the pain is; any one-sided weakness, speech change or vision change; fever, vomiting, neck stiffness, confusion, fit; pregnancy or recent birth; any head knock; the medicines they take and their allergies; whether they get migraines.

Scripts you can send right now

To the school: "[Child]'s family member is being taken to hospital by ambulance and I am with them, so [child] will be late or absent today. Please tell [child] the family is safe and that I will collect them at [time]."

To the relative next door or nearby: "Please keep [child] with you and take them to [school or activity] until I message. The person unwell has gone to hospital by ambulance for a sudden worst-ever headache, and the hospital needs to see them now, so I will not be at home today. If anything changes with them before the ambulance leaves, please call the emergency number yourself."

To the dispatcher: "Sudden worst-ever headache, peaked within seconds, started at [time]. They are [age]. They have [known conditions] and take [medicines]. They have [none, one-sided weakness, speech change, vomiting, confusion, a fit]. We are going to [hospital]."

To work: "I have to leave now — a family emergency, taken by ambulance. I cannot promise when I will be back, so please treat today as covered by someone else."

What a good next 24 hours looks like

Success tonight is not "the pain went away at home". It is:

• The call is made, and the exact start time is written down and handed over.
• The hospital team has assessed them and decided on scans and observation. That decision is theirs, and it will be clearer in the next few hours than it is now.
• The children are fed, at school, or with someone you trust, so the household is not falling apart while you are in hospital.
• You have eaten, drunk something, and slept in shifts. A caregiver with nothing left cannot notice a change at three in the morning.

This is not a substitute for the crew's assessment, and I cannot tell you what they will find — only that the sooner they see this person, the better the options are.

One question

Which country or city are you in? I have not put a number in this message because I cannot check one for your area from here, and I would rather you dial your local emergency number now than read a number that might be wrong. If you tell me your city, I can look up the official service entry for it.

Source: merck-pro https://www.merckmanuals.com/professional/neurologic-disorders/stroke/subarachnoid-hemorrhage