Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Call emergency services if the person has a seizure, is difficult to wake, suddenly becomes weak, has severe breathing difficulty, or develops a sudden severe headache with confusion or loss of consciousness.
Seek urgent medical care if a baby has a soft spot that remains tense or bulging while calm and upright, especially with repeated vomiting, unusual sleepiness, marked irritability, or rapidly increasing head size.
These findings can occur when pressure inside the skull is raised.
Book a routine appointment if frontal bossing is newly noticed, is becoming more obvious, or looks uneven.
A baby or child should also be assessed if there are concerns about head growth, height, limb shape, feeding, hearing, vision, movement, or development.
It can still be discussed during a routine visit, particularly if you are unsure whether it is changing.
The article also says
A longstanding forehead shape without other symptoms is usually not an emergency.
Every sign above is quoted from the sofidex article on Frontal bossing. If you are not sure, err upward — it is always reasonable to be checked.