Head circumference is measured by using a soft ruler to measure the length by making a circle around the upper edge of the arch of the eyebrow, and the occipital node. Head circumference is measured by using a small soft tape measure around the upper edge of the arch of the eyebrow (the eyebrow area), the occipital node (the most prominent part of the back of the head) along the upper edge of the ears in a circle to measure the length of the head circumference. It is not good to have a head circumference that is too large or too small. Newborns have a head circumference of 33 to 34 centimeters, 46 centimeters at 1 year of age, 48 centimeters at 2 years of age, and only 6 centimeters between 2 and 15 years of age. Measurement of head circumference within 2 years of age is clinically significant; too small a circumference may be due to hypoplasia of the brain, premature closure of the cranial sutures, and too large a circumference may be due to hydrocephalus. If the head circumference is too small or too large, parents are advised to bring the patient to the doctor in time to avoid delay in treatment.