People diagnosed with macrocephaly will receive further medical tests to determine whether the syndrome is accompanied by particular disorders.

Pathologic macrocephaly may be due to megalencephaly (enlarged brain), hydrocephalus (abnormally increased cerebrospinal fluid), cranial hyperostosis (bone overgrowth), and other conditions.

Pathologic macrocephaly may be caused by congenital anatomic abnormalities, genetic conditions, or by environmental events.

[9] Diagnosis in infants includes measuring the circumference of the child's head and comparing how significant it falls above the 97.5 percentile of children similar to their demographic.

[citation needed] Although neurological disorders do not occur, temporary symptoms of benign and familial macrocephaly include: developmental delay, epilepsy, and mild hypotonia.

[citation needed] Other forms of macrocephaly include: Treatment varies depending on whether or not it occurs with other medical conditions in the child and where the cerebrospinal fluid is present.