When did you first notice that the baby's head seemed large?
Does the baby's head size seem to be increasing faster compared to the growth of the body?
Does the head seem larger all over?
Is the head growing more in a front-to-back pattern or in a side-to-side pattern?
What other symptoms are present (especially changes in brain or nervous system functions)?
The distance is measured in centimeters or inches and compared with:
Past measurments of a child's head circumference
Normal ranges for a child's sex and age (weeks, months) -- based on normal growth rates of infants' and children's heads
A careful physical exam will be done. Other milestones for growth and development will be checked.
In some cases, a single measurement is enough to confirm that there is a size increase that needs to be tested further. More often, repeated measurements of the head circumference over a period of time are needed to confirm that the head circumference is increased and the problem is getting worse.
Diagnostic tests vary depending on the cause, but often include:
Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.