2,701 articles
Hypovolemic shock
Hypovolemic shock: circulatory shock from critical intravascular volume loss (hemorrhage, GI, renal, or skin fluid losses), causing low preload and tissue hypoperfusion; treated with crystalloid or blood resuscitation and control of the source.
Iatrogenic Creutzfeldt-Jakob disease
Iatrogenic Creutzfeldt-Jakob disease (iCJD): CJD acquired via contaminated medical treatment, mainly cadaveric growth hormone and dura mater grafts; under 1% of CJD cases, incubation up to decades.
ICD classification of hypertensive heart disease
The ICD classification of hypertensive heart disease is ICD-10 category I11, split into I11.0 with heart failure and I11.9 without, replacing ICD-9 code 402 and mapping to ICD-11 code BA01.
ICON1 study
ICON1 (NCT01933581) is a UK prospective observational cohort study of patients aged 75+ with non-ST-elevation acute coronary syndrome undergoing invasive care; it produced the FRAIL-HEART risk score, which outperformed GRACE 2.
Icteric sclera
Icteric sclera (scleral icterus, more accurately conjunctival icterus) is yellowing of the eye whites from excess bilirubin, appearing at roughly 2 to 3 mg/dL, an early sign of liver, biliary, or blood disease.
ICU-RESUS trial
ICU-RESUS (NCT02837497), a hybrid stepped-wedge cluster randomized trial in 18 US pediatric ICUs, 2016–2021, tested point-of-care CPR training plus debriefing; it did not significantly improve favorable neurologic survival (53.8% vs 52.4%).
Idiopathic multifocal choroiditis
Idiopathic multifocal choroiditis (IMFC, ORPHA:714154) is a rare inflammatory white-dot chorioretinopathy of unknown cause, affecting young myopic white women, with punched-out lesions, frequent choroidal neovascularization, and steroid or immunosuppressive treatment.
Idiopathic posterior uveitis
Idiopathic posterior uveitis: inflammation of the retina or choroid with no identified infection, systemic disease, or defined syndrome after workup; 27-51% of US/European uveitis; treated with corticosteroids plus immunosuppression.
IIHTT trial
IIHTT (Idiopathic Intracranial Hypertension Treatment Trial, NCT01003639): NORDIC's 165-participant randomized trial showing acetazolamide plus a low-sodium weight-reduction diet modestly improved visual field, papilledema, quality of life, and weight in IIH with mild visual loss.
Ileocecal valve
The ileocecal valve is the anatomical structure where the ileum opens into the cecum, controlling the flow of chyme into the large intestine and preventing backflow into the small intestine.
Ileum
The ileum is the final and longest segment of the small intestine, about 3 meters long, ending at the ileocecal valve and absorbing vitamin B12 and bile salts.
Iliac crest
Iliac crest (crista iliaca), the curved superior border of the ilium palpable at the waist; runs ASIS to PSIS, marks roughly L4 via the supracristal plane, anchors trunk and hip muscles, and serves for bone graft, marrow harvest, and Risser staging.
Iliopsoas
Iliopsoas: the hip musculotendinous unit of psoas major, psoas minor, and iliacus; the body's strongest hip flexor, inserting on the lesser trochanter, innervated by lumbar plexus and femoral nerve, and prone to tendinopathy, bursitis, abscess, and snapping hip.
Iliotibial tract
Iliotibial tract (iliotibial band, Maissiat's band): thickened lateral thigh fascia lata band from iliac crest to Gerdy's tubercle, aponeurosis for tensor fasciae latae and gluteus maximus; source of iliotibial band syndrome in runners.
Ilium (bone)
Ilium (os ilium), the largest and most superior of the three bones (with ischium and pubis) forming the hip bone; a flat bone with iliac crest, ala, and ASIS, fusing at the acetabulum in adolescence.
Immune Adherence Reaction
Immune adherence reaction: antibody- and complement-dependent binding of C3b-coated antigen to C3b receptor cells (CR1, CD35), mainly primate erythrocytes; basis of the IAHA serology test.
Immune Reconstitution
Immune reconstitution: recovery of immune function, especially T cells, after HIV, chemotherapy, or stem cell transplantation; includes incomplete CD4 recovery, IRIS, and transplant monitoring.
Impossible color
Impossible colors are color percepts, such as reddish green or the laboratory color olo, that no light spectrum can produce; they arise from opponent-process color coding or direct cone stimulation.
Inclusion body myopathy with Paget disease of bone and frontotemporal dementia
IBMPFD, now called multisystem proteinopathy (MSP1 when caused by VCP), is a rare autosomal dominant adult-onset disorder combining inclusion body myopathy, early Paget disease of bone, and frontotemporal dementia, with ALS and parkinsonism also in the spectrum.
Incretin
Incretins are gut hormones, principally GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide), secreted by intestinal K-cells and L-cells after meals; they amplify glucose-stimulated insulin secretion, produce the incretin effect, and ground diabetes and obesity drugs.
Index finger
Index finger (digit 2): the second human finger, key for precision pinch and pointing. Contributes 20% of lateral pinch and 50% of pronated power grip; has two independent extensor tendons; its loss cuts pinch and grip strength about 20%.
Infant
Infant: a baby in roughly the first year of life (Merck: 1 month to 1 year; WHO: 29 days to 12 months). Covers developmental domains, milestones, reflexes, feeding, sleep, immunization, and safe-sleep guidance.
Infant behavior & development
Infant Behavior & Development (Infant Behav Dev), Elsevier journal founded 1978 by Ablex, ISSN 0163-6383, publishing peer-reviewed research on infancy from prenatal to 36 months across cognitive, motor, perceptual, and social development; quarterly, MEDLINE and SSCI indexed, SJR Q2.
Infection of spleen
Infection of spleen (ICD-11 3B81.7), chiefly splenic abscess and acute septic splenitis: rare bacterial, fungal, or parasitic splenic infection, 0.1–0.7% incidence, treated with antibiotics, percutaneous drainage, or splenectomy.
Infectious epithelial keratitis
Infectious epithelial keratitis: rare, sight-threatening inflammation of the corneal epithelium from viral (mainly HSV-1), bacterial, fungal, or protist infection; dendritic ulcers; treated with oral acyclovir, valacyclovir, or topical antivirals.
Infectious intermediate uveitis
Infectious intermediate uveitis (ICD-11 9B66.1): infection-driven inflammation of the vitreous and peripheral retina, caused mainly by syphilis, tuberculosis, and Lyme disease, diagnosed by PCR, serology, and mNGS.
Infectious keratitis
Infectious keratitis, also called microbial or infective corneal ulcer, is corneal infection by bacteria, fungi, viruses, or Acanthamoeba; the leading cause of corneal blindness, diagnosed by scraping, culture, PCR, and confocal microscopy.
Inferior colliculus
The inferior colliculus (IC) is a paired midbrain structure serving as the main relay for auditory information traveling from the inner ear to the auditory cortex, supporting sound localization.
Inferior epigastric artery
Inferior epigastric artery (deep inferior epigastric artery, DIEA): artery of the anterior abdominal wall arising from the external iliac artery above the inguinal ligament, anastomosing with the superior epigastric artery, forming Hesselbach's triangle's lateral border, and at risk in trocar placement.
Inferior mesenteric artery
Inferior mesenteric artery (IMA), unpaired abdominal aorta branch supplying the hindgut. Arises near L3, branches into left colic, sigmoid, and superior rectal arteries; key in colorectal surgery and mesenteric collateral circulation.