Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
1
Is any of this happening now?
Call 911
Call emergency services for:
A sudden, extremely severe headache that reaches maximum intensity quickly
Headache with weakness, numbness, facial drooping, confusion, fainting, or difficulty speaking
Headache with a seizure
Headache with fever, a stiff neck, marked drowsiness, or a new rash
Severe headache with sudden loss of vision
These features are not typical of tension headache and need assessment for other causes.
And for anyone, someone who:
has sudden weakness or drooping on one side of the face or body, slurred speech, or sudden confusion
has had a seizure that will not stop, or does not wake up afterwards
Other emergency signs, for anyone
Someone who is struggling to breathe, gasping, choking, or cannot get words out
Someone who has chest pain, tightness or pressure lasting more than a few minutes
Someone who is unconscious, or cannot be woken
Someone who is bleeding heavily and it will not stop with firm pressure
Someone who has lips or skin that look pale, blue, grey or blotchy
Someone who you believe has taken an overdose or swallowed something poisonous
2
Is any of this happening?
Be seen today
Seek urgent medical assessment for a new headache during pregnancy or soon after giving birth, after a significant head injury, or alongside persistent vomiting.
You should also get prompt help for a new headache with scalp tenderness or jaw pain while chewing, especially after age 50.
And for anyone, someone who:
has a fever with a stiff neck, a rash that does not fade under pressure, or severe headache
is vomiting and cannot keep fluids down
has a new severe headache unlike any they have had before
3
Does any of this apply?
Book an appointment
Arrange a routine appointment if:
Headaches are happening regularly or becoming more frequent
You need pain medicine repeatedly
The symptoms are affecting work, sleep, study, or daily activities
Your headache pattern has changed
You are unsure whether the headaches are tension headaches or migraines
Every sign above is quoted from the sofidex article on Tension headache. If you are not sure, err upward — it is always reasonable to be checked.