Life and health

Disorders of iron metabolism

Disorders of iron metabolism (ICD-11 5C64.1) cover iron deficiency and iron overload conditions such as hemochromatosis, anemia of inflammation, IRIDA, and aceruloplasminemia, all tied to the hepcidin-ferroportin axis.

Disorders of lacrimal gland

Disorders of lacrimal gland (ICD-11 9A10) cover dacryoadenitis, Sjögren-related gland destruction, and epithelial or lymphoid tumors of the tear-producing gland in the superolateral orbit.

Disorders of magnesium metabolism

Disorders of magnesium metabolism (ICD-10 E83.4; ICD-11 5C64.4) cover hypomagnesemia and hypermagnesemia. Hypomagnesemia is common in hospitalized patients from GI, renal, or drug causes; hypermagnesemia is rare, mainly in kidney disease.

Disorders of neutrophil chemotaxis

Disorders of neutrophil chemotaxis (ICD-11 4B01.01) are conditions in which neutrophils cannot migrate along chemotactic gradients to infections, seen in LAD types I-IV, RAC2 and actin defects, Shwachman-Diamond, and hyper-IgE syndrome.

Disorders of neutrophil function

Disorders of neutrophil function (ICD-11 4B01): inherited or acquired defects in neutrophil adhesion, chemotaxis, or killing, including chronic granulomatous disease, leukocyte adhesion deficiency, MPO and G6PD deficiency, and CARD9 deficiency.

Disorders of nucleotide metabolism

Disorders of nucleotide metabolism, also called inborn errors of purine and pyrimidine metabolism, are heritable enzyme defects of nucleotide synthesis, salvage, or catabolism; over 30 known, including Lesch-Nyhan disease, ADA deficiency, and orotic aciduria.

Disorders of oral mucosa

Disorders of oral mucosa (ICD-11 DA01): inflammatory, ulcerative, infectious, immune-mediated, and potentially malignant conditions of the mouth's lining, including aphthous stomatitis, oral lichen planus, candidiasis, leukoplakia, and erythroplakia, diagnosed by clinical examination, biopsy, and direct immunofluorescence.

Disorders of orthostatic tolerance

Disorders of orthostatic tolerance (ICD-11 8D89): conditions causing symptomatic hypotension on standing, including reflex syncope, autonomic-failure syncope, POTS, and baroreflex failure.

Disorders of pyruvate metabolism

Disorders of pyruvate metabolism, chiefly pyruvate dehydrogenase complex deficiency (PDHA1, X-linked) and pyruvate carboxylase deficiency (autosomal recessive), inborn errors causing lactic acidosis and neurological dysfunction, managed with ketogenic diet and supportive care.

Disorders of refraction

Disorders of refraction, or refractive errors, are eye conditions where light fails to focus on the retina, causing blurred vision; the main types are myopia, hyperopia, astigmatism, and presbyopia.

Disorders of sex development

Disorders/differences of sex development (DSD), formerly called intersex, are congenital conditions with atypical chromosomal, gonadal, or anatomical sex development, classified as 46,XX, 46,XY, or sex chromosome DSD, managed by multidisciplinary teams.

Disorders of sodium metabolism

Disorders of sodium metabolism (ICD-11 5C64.6) are dysnatremias: hyponatremia, serum sodium below 135 mmol/L, and hypernatremia, above 145 mmol/L, caused by disturbed water balance regulated by vasopressin and thirst.

Disorders of surfactant metabolism

Disorders of surfactant metabolism, also called surfactant dysfunction disorders (ICD-11 CB04.2), are rare genetic lung diseases from SFTPB, SFTPC, ABCA3, and NKX2-1 mutations, causing neonatal respiratory distress or interstitial lung disease.

Disorders of urea cycle metabolism

Urea cycle disorders (UCDs), also called disorders of urea cycle metabolism, are inherited defects in eight urea cycle enzymes or transporters causing hyperammonemia; about half present neonatally, OTC deficiency is the most common form.

Disorders of vestibular function

Disorders of vestibular function (ICD-11 AB34, formerly ICD-10 H81): inner-ear and brain disorders of the balance system causing vertigo, dizziness, and imbalance; includes BPPV, Menière's disease, vestibular migraine, and bilateral vestibulopathy.

Disorders of zinc metabolism

Disorders of zinc metabolism (ICD-10 E83.2, ICD-11 5C64.2) cover zinc deficiency states, chiefly acrodermatitis enteropathica (SLC39A4/Zip4) and transient neonatal zinc deficiency (SLC30A2), treated with oral zinc.

Disorganised behaviour

Disorganised behaviour (ICD-11 MB23.6, 行動の統合不全) is a coded symptom: unpredictable, non-goal-directed activity such as shouting at strangers, equivalent to ICD-10-CM R46.2 and a positive symptom of psychotic disorders.

Disorganised thinking

Disorganised thinking, also known as formal thought disorder, is a disruption of associative thought evident in speech, counted among the positive symptoms of psychosis, particularly schizophrenia.

Disorganized schizophrenia

Disorganized schizophrenia, also called hebephrenia or hebephrenic schizophrenia, was a DSM-IV schizophrenia subtype marked by disorganized speech and behavior and flat affect; eliminated from DSM-5 and ICD-11.

Disparida

Disparida is an extinct monophyletic clade of Paleozoic fossil crinoids, Ordovician to Permian, defined by a single circlet of calyx plates below the radials and sister to the Cladida.

Dispersin

Dispersin: name of two bacterial proteins; Dispersin B (DspB), an A. actinomycetemcomitans GH20 glycoside hydrolase degrading PNAG biofilm matrix, and EAEC dispersin, an AggR-controlled 10-kDa anti-aggregation surface protein.

Disphyllum

Disphyllum is an extinct Devonian genus of fasciculate colonial rugose corals (family Disphyllidae), type species Cyathophyllum caespitosum Goldfuss 1826, cosmopolitan in Givetian and Frasnian limestones of Europe, Asia, and Australia.

Displacement of eyeball

Displacement of eyeball (眼球偏位), ICD-11 code 9A20 under Disorders of orbit, covers axial (proptosis, enophthalmos) and non-axial globe displacement; main adult cause is thyroid eye disease, measured by exophthalmometry or CT.

Sep 29, 2026

Displacement plethysmography

Displacement plethysmography is a family of diagnostic techniques measuring volume change of a limb or whole body by detecting displaced fluid or air, including air-displacement plethysmography.

Disposable Equipment

Disposable equipment: apparatus, devices, or supplies intended for one-time or temporary use (MeSH D004209); in medicine, single-use devices like syringes and catheters, regulated for reprocessing by FDA and EU MDR Article 17, with waste and carbon trade-offs versus reusables.

Disruptive behaviour

Disruptive behaviour (ICD-11 MB23.8) is a symptom category for behaviour causing disorder and turmoil in others or one's environment, such as angry outbursts, arguments, and disobedience, excluded from the related disruptive behaviour or dissocial disorders grouping.

Disruptive mood dysregulation disorder

Disruptive mood dysregulation disorder (DMDD), a DSM-5 depressive disorder added in 2013, involves chronic childhood irritability and frequent severe temper outbursts; created to curb pediatric bipolar misdiagnosis, with 3.3% community prevalence and no FDA-approved medications.

DissEcT trial

DissEcT (NCT06992453), Disentangling Microbiome Engraftment by Multi-omics of the Gut Ecosystem During Fecal Transplant, is a Rome-based trial using multi-omics to study FMT engraftment in rCDI, ulcerative colitis, and metabolic syndrome.

Dissecting cellulitis of the scalp

Dissecting cellulitis of the scalp (perifolliculitis capitis abscedens et suffodiens, Hoffman's disease) is a chronic inflammatory follicular occlusion disorder causing painful scalp nodules, sinus tracts, and scarring alopecia, mainly in African American men aged 20-40.