What does macrocephaly mean?
Macrocephaly is the medical term for an abnormally large head, usually identified when the head circumference is substantially greater than expected for a person’s age and sex. It is commonly used in pediatrics and neurology, particularly when assessing infants and children whose heads appear unusually large or are growing rapidly. The condition does not identify a cause by itself. A clinician may need to distinguish increased head circumference from increased brain volume, a finding called megalencephaly, and may investigate possible genetic, neurological, skeletal, or fluid-related explanations. Macrocephaly can sometimes be an isolated observation that causes no significant difficulty, but follow-up imaging and developmental assessment may be appropriate. The word is specialized and is rarely used in general conversation except when discussing a medical finding. Its name reflects its components: a prefix meaning “large” and a term meaning “head.”
nounAn abnormal enlargement of the head, usually identified when head circumference is significantly greater than expected for age and sex. It may reflect rapid cranial growth or an underlying neurological, genetic, or skeletal condition.
- A condition characterized by an abnormally large head or head circumference relative to age and sex.
"The infant was referred for further assessment after screening suggested macrocephaly."
"Prenatal imaging raised the possibility of macrocephaly, so the newborn was scheduled for follow-up examinations."
"Macrocephaly can be an isolated finding, although it may also occur in association with neurological or genetic disorders."
"The clinician explained that macrocephaly describes the size of the head and does not, by itself, establish the cause."
The plural is uncommon because the term usually refers to an individual clinical finding or condition.
"The report includes several cases of macrocephalies diagnosed during infancy."
A head that measures larger than expected can sometimes be a clue to rapid brain growth or an underlying medical condition.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does macrocephaly come from?
Macrocephaly combines a form of Greek makros, meaning “large,” with kephalē, meaning “head,” via the combining form -cephaly. The term developed in modern medical usage from the same Greek elements found in cognates such as cephalic and macrocephalous.
Related word forms
How macrocephaly is actually used
This is primarily a medical term. Clinicians may distinguish macrocephaly from megalencephaly, which refers specifically to increased brain volume; apparent macrocephaly can also result from fluid accumulation or differences in head shape.
Easily confused with macrocephaly
Macrocephaly describes an abnormally large head or head circumference, whereas megalencephaly refers specifically to an abnormally large brain.