Human health and medicine

Double aortic arch

Double aortic arch: a congenital heart defect with two aortic arches forming a vascular ring around the trachea and esophagus, causing breathing and swallowing symptoms; treated surgically with excellent outcomes.

Double chambered right ventricle

Double chambered right ventricle (DCRV), anomalous muscle bundles dividing the right ventricle into high- and low-pressure chambers, a rare congenital RVOT obstruction (0.5–2% of CHD) usually linked to VSD, often missed on echo, treated by surgical resection.

Double diffusion (immunology)

Double diffusion, or the Ouchterlony double immunodiffusion assay, is an immunological technique in which antigen and antibody diffuse toward each other through agar gel, forming precipitin lines.

Double eyelids

Double eyelids, also called creased upper eyelids, are upper eyelids with a visible supratarsal crease; about 50% of people of Asian descent lack one, and surgery can create it.

Double outlet left ventricle

Double outlet left ventricle (DOLV) is a rare congenital heart defect in which the aorta and pulmonary artery both originate from the morphologic left ventricle, usually with a ventricular septal defect.

Double outlet right ventricle

Double outlet right ventricle (DORV), also called double-outlet right ventricle, is a congenital heart defect where both the aorta and pulmonary artery arise from the right ventricle, usually with a VSD; treated by biventricular repair, single-ventricle palliation, or palliation.

Double tract reconstruction

Double tract reconstruction is a surgical reconstruction after proximal or total gastrectomy that routes food through two pathways, preserving duodenal transit and reducing reflux esophagitis compared with esophagogastrostomy.

Double-balloon endoscopy

Double-balloon endoscopy is an endoscopic technique in which two inflatable balloons grip the intestinal wall, allowing deep small-bowel examination and treatment without surgery, first reported in 2001.

Double-Balloon Enteroscopy

Double-balloon enteroscopy (DBE), invented by Hironori Yamamoto and first reported in 2001, is a balloon-assisted deep enteroscopy technique using an endoscope and overtube with two balloons; distinct from single-balloon and spiral enteroscopy.

Double-bundle anterior cruciate ligament reconstruction

Double-bundle anterior cruciate ligament reconstruction is a knee surgery that rebuilds a torn ACL with two tendon grafts, one for each functional bundle, to restore rotational stability.

Double-dummy technique

The double-dummy technique is a blinding method for randomized trials where treatments differ in appearance, so each participant takes an active drug and a matching placebo.

Double-row rotator cuff repair

Double-row rotator cuff repair is an arthroscopic technique that reattaches a torn rotator cuff tendon to the humerus using two rows of suture anchors for better healing.

Doublet chemotherapy

Doublet chemotherapy is a cancer treatment that combines two cytotoxic drugs given together in the same treatment cycles, the standard first-line backbone for advanced colorectal cancer with regimens such as FOLFOX or FOLFIRI.

Doubly labeled water

Doubly labeled water (DLW) is an isotope tracer method measuring total energy expenditure in free-living people, regarded as the gold standard since the first human study in 1982.

Douche

Douche: rinsing the inside of the vagina with water, vinegar, baking soda, or iodine solutions. Practiced by 29-92% of women worldwide, mainly for cleanliness; linked to bacterial vaginosis, PID, and preterm birth; not recommended by health authorities.

Oct 10, 2026

Douglas T. Prehn

Douglas T. Prehn, also known as Douglas Theodore Prehn, was an American United States Navy urologist who described Prehn's sign, used to distinguish testicular torsion from epididymitis.

Doula

Doula: trained non-medical birth support professional (Greek 'handmaiden') providing continuous physical, emotional, informational support before, during, after childbirth; Cochrane-linked to fewer cesareans, shorter labors; growing Medicaid coverage.

Dowling-Degos disease

Dowling-Degos disease (DDD, dark dot disease, reticular pigment anomaly of flexures) is a rare autosomal dominant genodermatosis causing reticulate hyperpigmentation of flexures after puberty, caused by KRT5, POFUT1, POGLUT1, PSENEN, or GLMN mutations.

Down syndrome

Down syndrome (trisomy 21): genetic condition from an extra chromosome 21 copy; ~1 in 640 US births; forms include free trisomy, Robertsonian translocation, mosaicism; features intellectual disability, heart defects, early Alzheimer's.

Downbeat nystagmus

Downbeat nystagmus (DBN), ICD-11 9C84.20, is the most common acquired central nystagmus: upward slow drift, downward quick phase, worsened by downgaze; caused by cerebellar or brainstem lesions, treated with aminopyridines.

Oct 20, 2026

Downward gaze deviation

Downward gaze deviation (ICD-11 9C83.12), also called downgaze palsy, is a conjugate downward eye deviation or supranuclear limitation of downward gaze; chronic isolated downgaze palsy with preserved vestibulo-ocular reflex points to progressive supranuclear palsy.

Doxacurium

Doxacurium (Nuromax, BW-A938U) is a long-acting nondepolarizing benzylisoquinolinium neuromuscular blocker, ED95 0.025 mg/kg, renal/biliary excretion, FDA-approved 1991, now discontinued.

Doxapram

Doxapram (Dopram) is an intravenous respiratory stimulant, first FDA-approved in 1965, acting on carotid chemoreceptors and medullary centers; used for postanesthesia and drug-induced respiratory depression, COPD hypercapnia, and refractory apnea of prematurity.

Doxazosin

Doxazosin (Cardura) is a quinazoline alpha-1 adrenergic blocker for hypertension and BPH symptoms. The ALLHAT trial stopped its hypertension arm in 2000 after doxazosin doubled heart failure risk versus chlorthalidone; it remains a second-line, BPH-focused drug.

Doxepin

Doxepin (Sinequan, Silenor) is a tricyclic antidepressant approved in 1969; at 3-6 mg it acts as a selective H1 antagonist for sleep-maintenance insomnia, and at higher doses treats depression and pruritus.

Doxercalciferol

Doxercalciferol (Hectorol) is a synthetic vitamin D2 analog prohormone activated hepatically by CYP27, used to suppress PTH in secondary hyperparathyroidism of stage 3-4 CKD and dialysis patients; US approved 1999, oral and injectable forms.

Doxifluridine

Doxifluridine (5'-DFUR, Furtulon, Ro 21-9738) is an oral fluoropyrimidine prodrug of 5-fluorouracil activated by thymidine phosphorylase; capecitabine is its liver-derived successor prodrug.

Doxofylline

Doxofylline, a xanthine bronchodilator introduced in 1987 as a theophylline alternative, treats asthma and COPD with bronchodilator and anti-inflammatory activity, a wider therapeutic window, no plasma monitoring, and weak PDE2A/A2A effects only.

Doxorubicin

Doxorubicin (Adriamycin) is an anthracycline chemotherapy antibiotic, FDA-approved 1974, that kills cancer cells via DNA intercalation and topoisomerase II inhibition; its dose-limiting toxicity is cumulative cardiotoxicity, mitigated by liposomal formulations and dexrazoxane.