NCIthesaurus has symptom appendix disease appendicitis ICD10CM:K37 NCI:C35145 DOID:10947 UMLS_CUI:C0003615 DOID:8337 MESH:D001064 SNOMEDCT_US_2025_09_01:155729003 An appendix disease that involves inflammation and infection of the appendix caused by the blockage of the lumen with a small, hard piece of stool, a foreign body or worms. Mucus backs up in the appendiceal lumen, causing bacteria that live inside the appendix to multiply. The infection has_symptom pain, in the upper abdomen initially and later in the lower abdomen, has_symptom nausea, has_symptom vomiting and has_symptom fever. acute appendicitis acute appendicitis with generalized peritonitis disease_ontology ICD9CM:540-543.99 DOID:10275 DOID:10276 acute appendicitis with peritoneal abscess nausea fever vomiting