Microcephaly is a condition in which a person's head size is much smaller than that of others of the same age and sex. Head size is measured as the distance around the top of the head. A smaller than normal size is determined using standardized charts.

What does small head size indicate?

Microcephaly is a medical condition in which the circumference of the head is smaller than normal because the brain has not developed properly or has stopped growing. Microcephaly can be present at birth or it may develop in the first few years of life.

Does a small head mean small brain?

Even though head size also depends on factors such as the muscularity of the head and thickness of the bone, it's very likely that a bigger head means a bigger brain. But Hurlburt says people with bigger brains aren't necessarily smarter than those with smaller ones.