Human health and medicine

Cold-stimulus headache

Cold-stimulus headache, also known as brain freeze, ice-cream headache, or Slurpee burn, is a common, short-lasting headache triggered by eating or breathing in something cold.

Cole-Carpenter syndrome (CLCRP1, OMIM 112240; also CLCRP2) is an extremely rare osteogenesis imperfecta-like bone fragility disorder with craniosynostosis, ocular proptosis, hydrocephalus, and distinctive facial features, caused by P4HB, SEC24D, or CRTAP mutations.

Colectomy

Colectomy is surgery removing part or all of the colon, also called colon resection or bowel resection. Types include hemicolectomy, proctocolectomy, and sigmoidectomy; done open, laparoscopically, or robotically for cancer, diverticulitis, and IBD.

Colestilan chloride

Colestilan chloride (MCI-196; brands BindRen, Cholebine, Japanese name コレスチミド) is a non-absorbed, non-calcium phosphate binder and bile acid sequestrant lowering phosphorus and LDL-C in dialysis patients; EU authorization withdrawn in 2015.

Colestipol hydrochloride

Colestipol hydrochloride, sold as Colestid, is a bile acid sequestrant resin that binds bile acids in the intestine to lower LDL cholesterol, first FDA approved in 1977.

Colestyramine

Colestyramine (cholestyramine, Questran) is a nonabsorbable anion-exchange resin bile acid sequestrant used for hypercholesterolemia, cholestatic pruritus, and bile acid diarrhea; developed at Merck in the late 1950s, it lowers LDL-C about 10-25% and requires separated dosing from other drugs.

Oct 20, 2026

Colfosceril palmitate

Colfosceril palmitate (Exosurf, Exosurf Neonatal), a protein-free synthetic lung surfactant of DPPC, hexadecanol, and tyloxapol (85:9:6), FDA approved August 1990 for neonatal RDS, inferior to animal-derived surfactants and withdrawn.

Colic

Colic: excessive, inconsolable crying in an otherwise healthy infant, defined by Wessel's rule of threes and Rome IV criteria; affects 17-25% of infants, peaks at 4-6 weeks, resolves by 3-4 months; also biliary, renal, and intestinal colic in adults.

Colistin

Colistin, also known as polymyxin E, is a polymyxin antibiotic used as a last-resort treatment for multidrug-resistant Gram-negative infections, returning to systemic use by the mid-1990s after decades of abandonment over toxicity.

Colitis

Colitis is inflammation of the colon (large intestine), with infectious, ischemic, microscopic, radiation, and IBD forms such as ulcerative colitis and Crohn's disease; symptoms include bloody diarrhea, and treatment depends on cause.

Collaborative care model

The collaborative care model is a healthcare delivery model in which a primary care provider, care manager, and psychiatric consultant jointly treat depression in primary care.

Oct 20, 2026

Collagen type III glomerulopathy

Collagen type III glomerulopathy, or collagenofibrotic glomerulopathy, a rare non-immune-mediated kidney disease with type III collagen deposits in glomerular mesangium and subendothelial space; about 100 cases, mostly Japanese; nephrotic proteinuria, no specific treatment.

Collagen, type XVII, alpha 1

COL17A1 (BP180, BPAG2) encodes type XVII collagen, a 180-kDa type II transmembrane hemidesmosomal protein anchoring epidermis to basement membrane; mutated in junctional epidermolysis bullosa and autoantigen in pemphigoid diseases.

Collagenous colitis

Collagenous colitis, a subtype of microscopic colitis first named by Lindström in 1976, causes chronic watery non-bloody diarrhea with a normal-looking colon; diagnosis needs biopsies showing a subepithelial collagen band ≥10 μm, and budesonide is first-line therapy.

Collapse Therapy

Collapse therapy: historical surgical treatment of pulmonary tuberculosis immobilizing the lung (artificial pneumothorax, thoracoplasty, plombage) so lesions rest and heal; obsolete after 1940s chemotherapy, revived for drug-resistant TB.

Collateral Circulation

Collateral circulation: naturally occurring artery-to-artery backup vessels (coronary, cerebral, peripheral) that enlarge by arteriogenesis under shear stress after arterial occlusion, measured by collateral flow index, and linked to better survival in coronary disease and stroke.

Collateral ligament reconstruction

Collateral ligament reconstruction is a surgical procedure that replaces a damaged knee collateral ligament with a tendon graft through bone tunnels, restoring valgus and varus stability.

Collateral ligament repair

Collateral ligament repair is a surgical procedure that reattaches a torn native collateral ligament to its bone attachment, preserving the patient's own tissue rather than using a tendon graft.

Collecting duct carcinoma

Collecting duct carcinoma, also called Bellini duct carcinoma, is a rare aggressive renal cell carcinoma subtype arising from the renal medulla, about 1% of kidney cancers, with median survival around 13-18 months and platinum-gemcitabine chemotherapy as mainstay systemic therapy.

Collecting duct system

Collecting duct system (kidney): ureteric bud-derived tubules draining nephrons; segments from connecting tubule to papillary duct; principal and intercalated cells; ADH/AQP2 water reabsorption, ENaC sodium handling, acid secretion; urine 0.5–10 L/day, up to 1200 mOsm/kg.

Colles' fracture

Colles' fracture, a dorsally displaced distal radius fracture from a fall on an outstretched hand, named after Abraham Colles; common in elderly, treated by closed reduction and casting or volar locking plating.

Colloid cyst

Colloid cyst: benign epithelial (neuroepithelial) cyst of the anterior third ventricle, 0.2-3% of benign intracranial tumors, causing obstructive hydrocephalus and rare sudden death; treated by endoscopic or microsurgical resection.

Coloboma

Coloboma (ocular coloboma, congenital ocular coloboma) is a birth defect in which part of the eye or eyelid tissue is missing, caused by failure of the embryonic fissure to close; affects about 1 in 10,000 people and can cause childhood blindness.

Coloboma of choroid and retina

Coloboma of choroid and retina (chorioretinal coloboma, ORPHA:98942) is a rare genetic birth defect with partial absence of retinal pigment epithelium and choroid, usually inferonasal, causing reduced vision and retinal detachment risk.

Coloboma of eyelid

Coloboma of eyelid (eyelid coloboma, coloboma palpebrale): a congenital full-thickness eyelid margin defect, usually upper lid, occurring in roughly 0.2-0.8 per 10,000 births, isolated or syndromic (Fraser, Goldenhar, Treacher Collins, CHARGE), risking exposure keratopathy and amblyopia.

Coloboma of iris

Coloboma of iris (iris coloboma, ICD-10 Q13.0) is a congenital gap in the iris from failed embryonic fissure closure, giving a keyhole pupil, photophobia; treated with tinted contacts or surgery.

Coloboma of macula

Coloboma of macula (macular coloboma; OMIM 120300) is a rare congenital chorioretinal maldevelopment of the macula, not caused by optic fissure closure failure, causing central vision loss and distinguished from toxoplasmosis by OCT.

Coloboma of optic disc

Coloboma of optic disc (optic disc coloboma, ORPHA 98947) is a rare genetic, inferiorly decentered bowl-shaped excavation of the optic disc from failed embryonic fissure closure, causing reduced vision and retinal detachment risk.

Colon capsule endoscopy

Colon capsule endoscopy is a diagnostic test in which the patient swallows a camera capsule that photographs the colon to detect polyps, colorectal cancer, and inflammation without sedation.