Human health and medicine

UMODCOVID19 study

UMODCOVID19 (NCT04316884) is a completed Uppsala University observational study of organ dysfunction and biomarkers in 380 ICU patients with COVID-19, led by Robert Frithiof, with daily blood, urine, and sputum sampling.

Unani medicine

Unani medicine (Unani Tibb, Greco-Arab medicine): traditional healing system rooted in Greek Hippocratic-Galenic medicine, transmitted via Arabic and Persian scholars, now practiced and regulated in India and Pakistan.

Unattended death

Unattended death (ICD-11 MH13; ICD-10 R98, "found dead") is a death occurring without medical attendance, requiring coroner or medical examiner investigation; certified causes differ from autopsy findings in about 30% of cases.

Uncinariosis

Uncinariosis (uncinariasis), ICD-11 1F6H, is infection with the dog and cat hookworm Uncinaria stenocephala; formerly a synonym for human hookworm disease. In humans it causes cutaneous larva migrans, a self-limited itchy creeping skin track.

Unclassified vasculitis

Unclassified vasculitis is a rare inflammatory disease of blood vessels that cannot be assigned to any known vasculitis category, sometimes covering recognized conditions the Chapel Hill nomenclature omits.

Uncombable hair syndrome

Uncombable hair syndrome (spun glass hair, pili trianguli et canaliculi, cheveux incoiffables) is a rare childhood hair shaft anomaly causing dry, frizzy, silvery hair that cannot be combed flat; caused by PADI3, TGM3, or TCHH mutations and improving by adolescence.

Oct 20, 2026

Uncomplicated crown-root fracture

Uncomplicated crown-root fracture (ICD-11 NA0D.04): traumatic tooth fracture through enamel, dentin, and cementum without pulp exposure, typically extending below the gum; treated by fragment removal, restoration, and 5-year follow-up.

Uncontrolled study

An uncontrolled study is a clinical or epidemiological study design lacking a comparison group, including single-arm trials, case series, and before-after studies, with high risk of bias.

UNCOVER-3 trial

UNCOVER-3 (NCT01646177): phase 3 trial of ixekizumab (Taltz) in 1,346 adults with moderate-to-severe plaque psoriasis, showing superiority over placebo and etanercept at week 12 and persistent efficacy through 108 weeks.

Undernutrition in children

Undernutrition in children: insufficient nutrient intake or utilization, manifesting as wasting, stunting, underweight, and micronutrient deficiencies; diagnosed by WHO growth-standard z-scores, linked to about 45% of under-5 deaths, and treated with ready-to-use therapeutic foods.

Underwater endoscopic mucosal resection

Underwater endoscopic mucosal resection (UEMR) is an endoscopic technique that removes gastrointestinal lesions by submerging them in water, avoiding submucosal injection, first reported in 2012.

Underweight

Underweight: body weight below the healthy range, defined as BMI under 18.5 kg/m² in adults (WHO grades thinness below 17.0) and BMI below the 5th percentile in children; a screening-based nutritional status with defined pediatric faltering-weight criteria.

Underweight in adults

Underweight in adults: BMI below 18.5 kg/m2 per WHO, CDC, and ICD-11 code 5B54. Covers thinness grades, health risks, MUAC screening, NICE nutrition support criteria, and US and global prevalence trends.

Undescended testicle, unilateral

Undescended testicle, unilateral (unilateral cryptorchidism, ICD-11 LB52.1): one testis fails to descend into the scrotum. Treated by orchidopexy before 12–18 months; fertility rate reduced but paternity preserved; elevated testicular cancer risk.

Undifferentiated carcinoma of esophagus

Undifferentiated carcinoma of esophagus (WHO 8020/3), a rare aggressive esophageal cancer lacking squamous, glandular, and neuroendocrine differentiation, often SMARCA4/SMARCA2-deficient, associated with Barrett esophagus and median survival 2.60 months.

Oct 20, 2026

Undifferentiated carcinoma of stomach

Undifferentiated carcinoma of the stomach, also called undifferentiated gastric carcinoma, is a rare, highly aggressive stomach cancer whose cells show no glandular, squamous, or neuroendocrine differentiation under the microscope.

Undifferentiated carcinoma of the corpus uteri

Undifferentiated carcinoma of the corpus uteri, also called endometrial undifferentiated carcinoma (UEC), is a rare, aggressive uterine cancer of undifferentiated cells, first distinctly defined in 2005.

Undifferentiated carcinoma with osteoclast-like giant cells of pancreas

Undifferentiated carcinoma with osteoclast-like giant cells of the pancreas (UC-OGC, UCOGCP, ICD-O 8035/3) is a rare ductal adenocarcinoma variant, under 1% of pancreatic malignancies, with better survival than conventional PDAC.

Undifferentiated connective tissue syndrome

Undifferentiated connective tissue syndrome (UCTD) is a systemic autoimmune condition with symptoms and autoantibodies suggesting a connective tissue disease that fail classification criteria for lupus, scleroderma, Sjögren's, or related defined diseases.

Oct 20, 2026

Undifferentiated embryonal sarcoma of the liver

Undifferentiated embryonal sarcoma of the liver (UESL), also called embryonal hepatic sarcoma, is a rare malignant mesenchymal childhood liver tumor, third most common after hepatoblastoma and HCC, peaking at ages 6–10, treated by resection plus chemotherapy.

Undifferentiated juvenile idiopathic arthritis

Undifferentiated juvenile idiopathic arthritis (JIA) is the ILAR classification category for childhood arthritis of unknown cause that fits no defined subtype, or fits two or more at once.

Undifferentiated pleomorphic sarcoma

Undifferentiated pleomorphic sarcoma (UPS), formerly malignant fibrous histiocytoma, is an aggressive soft tissue sarcoma, 5-10% of adult cases, typically in deep extremity tissue, treated by wide resection with radiation and, increasingly, immunotherapy.

Unecritinib fumarate (TQ-B3101)

Unecritinib fumarate (TQ-B3101, Anboni, 富马酸安奈克替尼) is an oral ALK/ROS1/c-Met inhibitor approved in China April 2024 for ROS1-positive advanced NSCLC; phase II ORR 80.2%, median PFS 16.5 months.

Unexplained infertility

Unexplained infertility (UI) is a diagnosis of exclusion: no cause found after a full infertility workup. WHO criteria, ASRM and NICE treatment guidance (OS-IUI, IVF), and limited evidence quality distinguish it.

Unhappy triad

Unhappy triad (O'Donoghue triad, terrible triad): combined knee injury of ACL, MCL, and meniscus tear from valgus force with rotation; lateral meniscus now known more common than medial.

Unibrow

Unibrow, or synophrys (monobrow), is fusion of the eyebrows at the midline above the nose. Usually a normal variation linked to PAX3; prized in antiquity, often removed in the modern West.

Unicervical bicornuate uterus

Unicervical bicornuate uterus, also called bicornuate unicollis uterus, is a rare non-syndromic Müllerian malformation with two uterine horns and one cervix (ICD-10 Q51.3, ORPHA:180114), caused by incomplete Müllerian duct fusion and associated with recurrent pregnancy loss and preterm birth.

Unicompartmental knee arthroplasty

Unicompartmental knee arthroplasty (UKA) is a surgical procedure that resurfaces only the damaged compartment of the knee with a partial prosthesis, preserving the cruciate ligaments and native bone.

Unicuspid aortic valve

Unicuspid aortic valve (UAV), single-leaflet congenital aortic valve, first reported 1958; prevalence 0.02% on adult echo, 4-6% of aortic stenosis valve replacements; acommissural vs unicommissural subtypes; often misdiagnosed as bicuspid; treated by repair or Ross procedure.