Human health and medicine

Chronic tubulo-interstitial nephritis

Chronic tubulo-interstitial nephritis (CTIN, chronic interstitial nephritis, ICD-10 N11, ICD-11 GB55) is gradual tubulointerstitial inflammation, fibrosis, and tubular atrophy causing slow renal decline over years, from drugs, toxins, reflux, metabolic, or immune causes.

Chronic ulcerative stomatitis

Chronic ulcerative stomatitis (CUS), first described in 1990, is a rare immune-mediated oral disease with painful erosions resembling lichen planus, diagnosed by SES-ANA IgG against ΔNp63α on direct immunofluorescence and treated with hydroxychloroquine (ICD-11 DA01.12).

Chronic urate nephropathy

Chronic urate nephropathy, also called chronic gouty nephropathy, is chronic kidney disease from urate crystal or microtophi deposition in the renal medullary interstitium, causing tubular obstruction, macrophage inflammation, and interstitial fibrosis; treated only when hyperuricemia is symptomatic.

Chronic vascular disorders of intestine

Chronic vascular disorders of intestine, ICD-10-CM K55.1 and ICD-11 DD31, covers long-standing intestinal blood-flow disorders, chiefly chronic mesenteric ischaemia from atherosclerosis, causing postprandial pain and weight loss.

Chronic venous insufficiency

Chronic venous insufficiency (CVI), also called venous reflux disease, is impaired leg-vein return of blood from valve failure or obstruction, causing swelling, varicose veins, and ulcers; diagnosed by duplex ultrasound and treated with compression and ablation.

Chronic vestibular syndrome

Chronic vestibular syndrome (ICD-11 AB32): persistent vertigo, dizziness, or unsteadiness lasting months to years. Main causes include PPPD, bilateral vestibulopathy, and presbyvestibulopathy.

Chronic viral hepatitis

Chronic viral hepatitis (ICD-11 1E51) is liver disease from hepatitis B, C, D, or E infection lasting six months or longer; 240 million people have chronic HBV and 1.3 million died in 2024.

Chronic visceral acid sphingomyelinase deficiency

Chronic visceral acid sphingomyelinase deficiency, formerly Niemann-Pick disease type B (OMIM 607616), is an autosomal recessive SMPD1 lysosomal storage disease with hepatosplenomegaly, interstitial lung disease, dyslipidemia, no neurodegeneration, treated with olipudase alfa ERT.

Chronic widespread pain

Chronic widespread pain (CWP), ICD-11 MG30.01, fibromyalgia-related diffuse pain in at least 4 of 5 body regions for over 3 months with distress and disability; distinguished from chronic secondary pain by absence of an adequately explaining condition.

ChronicGI study

ChronicGI (Gut Microbiota in Chronic GI Diseases, NCT06532110) is a recruiting McMaster University observational cohort study of 260 people with IBD, IBS, celiac disease, microscopic colitis, or functional diarrhea versus controls, combining endoscopy biopsy microbiota sampling with germ-free mouse colonization experiments.

CHRONOHOSPI study

CHRONOHOSPI (NCT04113876), a Spanish multicenter observational study by Instituto de Salud Carlos III, measured circadian health and sleep in 975 hospitalized adults across 13 hospitals using Kronowise devices.

CHRONOS trial

LIBERTY AD CHRONOS (NCT02260986) is a 1-year phase 3 trial of dupilumab plus topical corticosteroids in 740 adults with moderate-to-severe atopic dermatitis; week-16 EASI-75 64-69% vs 23% placebo. Distinct from the CHRONOS panitumumab colorectal cancer trial.

Sep 29, 2026

Chronotherapy

Chronotherapy is a treatment strategy that times drug administration or other therapies to the patient's circadian rhythm, seeking to maximize efficacy and minimize toxicity; it applies chronopharmacology.

CHST3-related skeletal dysplasia

CHST3-related skeletal dysplasia, also called recessive Larsen syndrome or SED Omani type, is an autosomal recessive disorder from biallelic CHST3 variants causing congenital knee, hip, and elbow dislocations, clubfeet, prenatal-onset short stature, and progressive kyphosis.

Chudley-McCullough syndrome

Chudley-McCullough syndrome (CMS, MIM 604213), a rare autosomal-recessive GPSM2-related disorder: severe congenital sensorineural deafness with distinctive brain malformations (callosal agenesis, polymicrogyria, heterotopia) but usually preserved cognition.

Chuvash erythrocytosis

Chuvash erythrocytosis, also called Chuvash polycythemia, is a rare genetic disorder causing excess red blood cells, endemic to Russia's Chuvash Republic and caused by a homozygous VHL gene mutation.

Chvostek sign

Chvostek sign: ipsilateral facial muscle twitch after tapping the facial nerve, described by Franz Chvostek in 1876. Positive in 10-25% of healthy people and absent in 30% of hypocalcemic patients, so a poor hypocalcemia test.

Chylomicron

Chylomicrons are the largest, least dense lipoproteins (75–1,200 nm, apoB-48 particles) assembled in intestinal enterocytes to carry dietary triglycerides via lacteals and the thoracic duct; lipoprotein lipase converts them to remnants cleared by the liver.

Chylomicron retention disease

Chylomicron retention disease (Anderson disease, CMRD) is a rare autosomal recessive fat-malabsorption disorder caused by biallelic SAR1B mutations blocking COPII chylomicron secretion, presenting in infancy with failure to thrive, steatorrhea, and hypocholesterolemia with normal triglycerides.

Chylothorax

Chylothorax: chyle accumulation in the pleural space, usually from thoracic duct injury or obstruction. Also chylous pleural effusion. Diagnosed by pleural triglyceride >110 mg/dL; caused mostly by surgery or lymphoma.

Chylous ascites

Chylous ascites: leakage of triglyceride-rich lymph (chyle) into the peritoneal cavity, milky fluid with triglyceride >200 mg/dL; caused by malignancy, cirrhosis, tuberculosis, or lymphatic injury; treated conservatively first.

Chylous effusion

Chylous effusion (chylothorax): accumulation of chyle in the pleural space, about 3% of pleural effusions. Diagnosed by pleural triglyceride >110 mg/dL; caused mainly by trauma, surgery, and malignancy, especially lymphoma.

Chyluria

Chyluria, also called milky urine or suklameha, is chyle in urine from a lymphatic-urinary fistula, usually caused by Wuchereria bancrofti filariasis in Asia and Africa, treated conservatively, by sclerotherapy, or surgery.

Chyme

Chyme is the acidic semifluid mass of partly digested food formed in the stomach and released through the pylorus into the duodenum, where bile and pancreatic juice neutralize it; distinct from chyle, the milky fat-rich lymph of the small intestine.

Chymopapain

Chymopapain (Chymodiactin, Discase), a papaya-latex cysteine endopeptidase (EC 3.4.22.6), was injected into herniated lumbar discs for chemonucleolysis; FDA-approved November 10, 1982, later discontinued, mainly over anaphylaxis risk.

Ci-1

Ci-1 (CVCL_1861, CI-1, Ci1) is a human B-cell non-Hodgkin lymphoma cancer cell line established in 1981 from the ascites of a 38-year-old woman, distributed by DSMZ as ACC-570, with ~50-hour doubling time and latent EBV.

Cicatricial lagophthalmos

Cicatricial lagophthalmos, a mechanical form of lagophthalmos (ICD-11 9A03.40), is incomplete eyelid closure caused by scarring after eyelid surgery, trauma, or burns, treated with lubrication and scar release with grafting.

Cicatrizing conjunctivitis

Cicatrizing conjunctivitis, also called cicatricial conjunctivitis, is a rare vision-threatening group of disorders causing conjunctival inflammation and scarring, most often from mucous membrane pemphigoid or Stevens-Johnson syndrome.

Cicely Williams

Cicely Delphine Williams (1893–1992), Jamaican paediatrician who described kwashiorkor on the Gold Coast, led the 1939 "Milk and Murder" campaign against artificial infant feeding, survived Changi internment, and was WHO's first maternal and child health chief.