Human health and medicine

Nasal cannula

Nasal cannula: a two-pronged tube delivering supplemental oxygen through the nostrils. Low-flow versions give 24-44% FiO2 at 1-6 L/min; heated high-flow versions (HFNC) deliver up to 60 L/min with dead-space washout and PEEP.

Nasal cavity

Nasal cavity: the paired air space of the nose, also called nasal chambers, extending from nares to choanae. It warms, humidifies, and filters air, drains the paranasal sinuses, and houses olfactory receptors in its superior olfactory region.

Nasal concha

Nasal concha (turbinate): curved bony projection from the lateral nasal wall; three pairs (inferior, middle, superior) plus a variable supreme turbinate; middle and superior from ethmoid, inferior a separate bone; warm, humidify, and direct airflow.

Nasal congestion

Nasal congestion (stuffy nose) is a feeling of nasal or facial fullness from inflamed, swollen nasal tissue, caused by rhinitis, infections, allergies, irritants, or structural blockage; treated mainly with intranasal corticosteroids, saline, and antihistamines.

Nasal cycle

Nasal cycle: ultradian rhythm of alternating congestion and decongestion of the nasal turbinates, shifting airflow dominance between nostrils every ~2 hours awake and ~4.5 hours asleep, present in 70–80% of adults, driven by autonomic tone and first described by Kayser in 1895.

Nasal dermoid cyst

Nasal dermoid sinus cyst (NDSC), congenital midline nasal mass of children, incidence 1:20,000-40,000 births, ectodermal inclusion origin, may extend intracranially, MRI-based diagnosis, treated by surgical excision.

Nasal diphtheria

Nasal diphtheria, a mild chronic form of respiratory diphtheria limited to the nose, caused by toxigenic or nontoxigenic Corynebacterium diphtheriae; about 2% of cases, marked by bloody nasal discharge and often missed.

Nasal endoscopy

Nasal endoscopy, also called rhinoscopy, is a procedure in which a scope is passed through the nostril to examine the nasal cavity and sinus openings.

Nasal glial heterotopia

Nasal glial heterotopia (nasal glioma) is a rare, nonhereditary congenital mass of ectopic neuroglial tissue in or near the nose, without CNS connection; extranasal 60%, intranasal 30%, mixed 10%; complete excision is curative.

Nasal irrigation

Nasal irrigation (nasal lavage, saline nasal wash, neti pot rinsing) flushes the nasal cavity with saline to clear mucus and mediators; used for rhinosinusitis, allergic rhinitis, and colds; requires sterile or boiled water.

Nasal polyp

Nasal polyp, also called nasal polyposis or CRSwNP, is a painless inflammatory growth in the nose or sinuses, usually eosinophilic type 2 inflammation, treated with steroids, surgery, and biologics like dupilumab.

Nasal Provocation Tests

Nasal provocation test, also called nasal allergen challenge (NAC) or NAPT, applies allergen to the nasal mucosa to confirm allergic rhinitis, local and occupational rhinitis, and immunotherapy candidacy; EAACI 2018 standardized it bilaterally at 0.1 mL per nostril.

Nasal septum

Nasal septum (septum nasi): the midline bone-and-cartilage partition dividing the nasal cavity into two halves, formed by the ethmoid's perpendicular plate, vomer, and quadrangular cartilage; commonly deviated, corrected by septoplasty.

Nasal septum deviation

Nasal septum deviation (deviated septum, deviated nasal septum) is an off-center nasal septum, present in most people to some degree. It causes one-sided nasal obstruction, headaches, and snoring; septoplasty outperformed steroid and saline sprays in the NAIROS trial.

Nasal step

Nasal step, a glaucomatous visual field defect first described by Rönne in 1909: a sensitivity difference above and below the nasal horizontal midline, a nerve fiber bundle defect that begins as a scotoma.

Nasal Surgical Procedures

Nasal surgical procedures (septoplasty, rhinoplasty, turbinate reduction, nasal valve repair) operate on nasal structures to improve breathing, repair deformities, or change appearance; over 1.1 million rhinoplasties were performed worldwide in 2022.

Nasal swab

A nasal swab, also called a nasopharyngeal swab, collects mucus and respiratory cells from the nostril or nasopharynx to diagnose infections such as COVID-19, influenza, and RSV.

NASH trial

NASH trial: clinical studies testing drugs in nonalcoholic steatohepatitis, notably Gilead's simtuzumab (GS-6624) phase 2b trials NCT01672866 and NCT01672879 in 477 patients, terminated at 96 weeks for lack of efficacy, alongside failed selonsertib, emricasan, and GR-MD-02 programs.

Nasika Curna

Nasika Curna (Nāsikā cūrṇa), also Nasika Churna, is an official Ayurvedic Formulary of India herbal powder (AFI000622) administered through the nose as nasya, indicated for chronic rhinitis, headache, and halitosis, with twelve recorded ingredients.

Nasoalveolar molding

Nasoalveolar molding, also called presurgical nasoalveolar molding, is an orthodontic treatment for cleft lip and palate that reshapes the nose before surgical repair at 3 to 6 months.

Nasoendoscopy

Nasoendoscopy, also known as flexible nasendoscopy (FNE), is a diagnostic procedure in which a narrow flexible endoscope is passed through the nose to inspect the nasal cavity, nasopharynx, and larynx.

Oct 20, 2026

Nasolacrimal duct cyst

Nasolacrimal duct cyst (dacryocystocele, dacryocele): congenital cyst of the tear drainage duct, presenting at birth as a bluish medial canthal mass, causing tearing, dacryocystitis, and nasal obstruction; managed first conservatively, then surgically.

Nasolacrimal duct obstruction

Nasolacrimal duct obstruction (blocked tear duct) is blockage of tear drainage from eye to nose, congenital (valve of Hasner, resolves spontaneously in ~90% of infants) or acquired (inflammation, trauma, tumors), treated by massage, probing, intubation, or dacryocystorhinostomy.

Nasolaryngoscopy

Nasolaryngoscopy, also called fiberoptic nasendoscopy, is an office-based endoscopic exam in which a thin flexible scope passed through the nose inspects the nasal cavity, pharynx, and larynx.

Nasopalpebral lipoma-coloboma syndrome

Nasopalpebral lipoma-coloboma syndrome (NPLCS, OMIM 167730) is an extremely rare autosomal dominant congenital syndrome with eyelid and nasopalpebral lipomas, bilateral eyelid colobomas, telecanthus, and maxillary hypoplasia.

Nasopharyngeal myiasis

Nasopharyngeal myiasis (鼻咽頭ハエ症), ICD-11 1G01.1 / ICD-10 B87.3, is fly-larva infestation of the nose and nasopharynx, caused mainly by Oestrus ovis and Chrysomya bezziana, treated by larval removal plus ivermectin.

Nasopharyngoscopy

Nasopharyngoscopy is an office-based otolaryngology procedure in which a thin flexible or rigid scope passed through the nostril of an awake patient inspects the nasopharynx and larynx, used for hoarseness, sleep apnea, and detecting nasopharyngeal carcinoma.

Nasotracheal intubation

Nasotracheal intubation is an airway management procedure in which an endotracheal tube is passed through the nose into the trachea, leaving the mouth free for surgery.

Oct 20, 2026

NASOVAC Influenza Vaccine, Live Attenuated Freeze Dried

NASOVAC Influenza Vaccine, Live Attenuated (Human) Freeze-Dried, also called Nasovac, is a WHO-prequalified intranasal live attenuated pandemic H1N1 influenza vaccine by Serum Institute of India, prequalified 26 November 2012 (FVP-P-257/258), now listed as no routine production.