School avoidance does not arrive suddenly. It builds. There are almost always early signals quiet indicators that participation is becoming harder to sustain.
The early signals of unsustainable participation typically include: increasing recovery time after school, sleep disruption, physical symptoms on school mornings that resolve during holidays, and Sunday evening distress.
Later signals include: selective mutism in school settings, loss of friendships or social withdrawal, refusal to discuss school, and eventually refusal to get dressed or leave the house.
By the time a child refuses to attend school, the unsustainability has usually been present for months or years. The refusal is not the problem it is the end-point of a trajectory that was visible much earlier.
Families often know this intuitively. They feel that something is wrong long before the data confirms it. This knowledge deserves to be taken seriously.