What does aneurysm mean?
An aneurysm is an abnormal, localized swelling or ballooning of the wall of a blood vessel — most often an artery — caused by a weakness in the vessel wall. Under the pressure of circulating blood, the weakened area stretches outward, forming a sac or bulge that may grow slowly over years. Aneurysms can occur anywhere in the body but are most frequently discussed in connection with the brain and the aorta, the body's largest artery. Many remain silent and are discovered incidentally on scans, but if one ruptures it can cause severe internal bleeding and is a medical emergency. The word entered English in the early seventeenth century from Latin and ultimately derives from the Greek aneurysma, meaning 'a widening.' In usage, the term is almost entirely clinical, appearing in medicine, health journalism, and accounts of sudden illness, where it carries connotations of hidden danger and gravity.
nounAn abnormal, localized bulging or ballooning of the wall of a blood vessel, typically an artery, caused by weakness in the vessel wall.
- A permanent, abnormal dilation or bulge in the wall of a blood vessel, especially an artery, resulting from weakness of the vessel wall.
"The scan revealed a small aneurysm at the base of his brain."
"Doctors monitored the aortic aneurysm closely to ensure it did not enlarge further."
"She survived a ruptured brain aneurysm thanks to emergency surgery."
The standard English plural is formed regularly with -s. The learned Latinate plural "aneurysmata" occasionally appears in older or highly formal medical writing but is rare today.
"Patients with multiple aneurysms may require staged treatment over several months."
The word comes from the Greek for 'a widening' — because an aneurysm is literally your artery stretching wider than it should.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of aneurysm
The word "aneurysm" entered English in the early seventeenth century, borrowed from Latin aneurysma, which itself came from the Greek aneurysma meaning "a widening." The Greek term combines ana- ("up" or "throughout") with eurys ("broad" or "wide"), so the original sense was literally a broadening or dilatation — an apt description of what happens when a weakened vessel wall balloons outward. The adjective form aneurysmal is derived directly from the noun.
Related word forms
How aneurysm is actually used
Strictly a medical term used in clinical and health-reporting contexts rather than everyday conversation; it carries inherently serious connotations because aneurysms can rupture and cause life-threatening bleeding. The plural is regular (aneurysms), though the Latin-derived plural "aneurysmata" appears rarely in older texts.
Easily confused with aneurysm
"Aneurism" is simply an older or alternative spelling of the same word; "aneurysm" is now the standard spelling in modern medical usage.