Rare diseases · Sign or symptom
Pyloric stenosis
HP:0002021
What it means
Pyloric stenosis, also known as infantile hypertrophic pyloric stenosis, is an uncommon condition in infants characterized by abnormal thickening of the pylorus muscles in the stomach leading to gastric outlet obstruction. Clinically infants are well at birth. Then, at 3 to 6 weeks of age, the infants present with projectile vomiting, potentially leading to dehydration and weight loss.
Pyloric stenosis occurs in the first few months of life.
Rare diseases that can present with this40
Very common80–99%
3Common30–79%
4Sometimes5–29%
29- 1p36deletion syndrome
- 2q37microdeletion syndrome
- Agammaglobulinemia-microcephaly-craniosynostosis-severe dermatitis syndrome
- Arterial tortuosity syndrome
- Autosomal dominant centronuclear myopathy
- Autosomal recessive cutis laxa type 1
- Cornelia de Lange syndrome
- Distal 22q11.2 microdeletion syndrome
and 21 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: Infantile hypertrophic pyloric stenosis · Pylorus stenosis
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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.