Rare diseases · Sign or symptom
Vascular dilatation
Wider than typical opening or gap
HP:0002617
What it means
An abnormal increase in the diameter of an artery or vein, either as a diffuse dilatation or as a localized, sac-like outpouching of the vessel wall (aneurysm).
Aneurysm is considered a severe form of dilatation.
In everyday care
Most people with this sign do not have a rare disease — it appears in common conditions far more often. These general reference pages cover the same topic:
Rare diseases that can present with this23
Very common80–99%
5Sometimes5–29%
13- Autosomal dominant hyper-IgE syndrome due to STAT3 deficiency
- Autosomal recessive cutis laxa type 1
- Congenital Gerbode defect
- Coronary arterial fistula
- Glossopharyngeal neuralgia
- Isolated polycystic liver disease
- Kyphoscoliotic Ehlers-Danlos syndrome due to lysyl hydroxylase 1 deficiency
- Microcephalic osteodysplastic primordial dwarfism type II
and 5 more in this range
The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.
Part of the broader category
Also called: Aneurysm · Aneurysmal dilatation · Aneurysmal disease · Aneurysms
Tracking symptoms like this for someone? Eleplan keeps symptoms, diagnoses, medications and every specialist in one plan.
Start free with EleplanThis page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.