Increased head circumference is when the measured distance around the widest part of the skull is larger than expected for the child's age and background.
The health care provider usually finds macrocephaly during a routine well-baby exam.
The health care provider will take a medical history and will perform a physical examination.
Medical history questions may include:
- Time pattern
- When did you first notice that the baby's head seemed large?
- Does the baby's head size seem to be increasing faster in proportion 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)?
Physical examination may include repeated measurements of the head circumference over a period of time to confirm that the head circumference is significantly increased. In some cases a single measurement is enough to confirm a significant increase.
Diagnostic tests may vary depending on the suspected cause, but often include:
After seeing your health care provider:
If your health care provider diagnosed the cause of increased head circumference, you may want to note that diagnosis in your personal medical record.
A newborn's head is usually about 2 centimeters larger than the chest size. Between 6 months and 2 years, both measurements are about equal. After 2 years, the chest size becomes larger than the head.
A series of measurements over time that show an increased rate of head growth often can provide more valuable information than a single measurement that is larger than expected.
Increased pressure in the head (increased intracranial pressure) often accompanies increased head circumference. Symptoms associated with this condition include:
See also: Bulging fontanelles
Review Date: 5/13/2009
Reviewed By: 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.
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