Glottis is the middle of the three laryngeal compartments, situated between the supraglottis above and the subglottis below, and is defined structurally as the true vocal folds (vocal cords) together with the rima glottidis — the triangular opening between them — and functionally as the primary phonatory and airway-protective organ of the larynx. The true vocal folds are composed of a layered microstructure: from deep to superficial, the vocalis muscle (thyroarytenoid), the vocal ligament, and the stratified squamous epithelium of the cover — this layered architecture is critical because disruptions at any level (scarring, nodules, paralysis) affect voice quality differently and are addressed with distinct surgical approaches and CPT codes.
The rima glottidis changes shape dynamically: it is a narrow wedge at rest during quiet breathing, a wide triangle during forced inspiration, and a narrow slit during phonation when the vocal folds adduct and vibrate against each other to produce sound; abduction and adduction are controlled by the cricoarytenoid joints and driven primarily by the recurrent laryngeal nerve (RLN), making RLN injury — most commonly from thyroid surgery, malignancy, or cardiac/thoracic surgery — the leading cause of glottic dysfunction coded to J38.01 (unilateral) or J38.02 (bilateral). The most clinically and oncologically significant glottic condition is squamous cell carcinoma of the glottis, coded to C32.0, which has the most favorable prognosis of all laryngeal subsites due to early symptom presentation (dysphonia) and the sparse lymphatic drainage of the true vocal cord mucosa, resulting in a lower rate of occult nodal metastasis compared to supraglottis (C32.1) or subglottis (C32.2). The glottis is commonly confused with the larynx as a whole — the larynx is the entire organ containing all three subcompartments, while the glottis is specifically the vocal fold level only; precise subsite documentation is not only clinically important but drives ICD-10-CM site-specific code assignment and tumor staging.
Greek glōttis (GLOHT-is), from glōtta / glōssa (GLOHS-ah)
“tongue,” “mouth of the windpipe,” “the vocal apparatus” — the combining root referring to the vocal structure of the larynx; the Attic Greek dialect used glōtta while Ionic used glōssa
Noun-forming suffix — indicating “anatomical structure” or “part”
The term entered English in the 1570s-1580s as glottis (noun), directly from Greek glōttis — the diminutive form of glōtta (“tongue, mouthpiece”) — literally “the little tongue / the opening of the windpipe.” The root glōtt- (“vocal apparatus”) is the parent of the entire -glott- root family used throughout laryngeal anatomy: epiglottis (epi- + glottis → upon the glottis), supraglottis (supra- + glottis → above the glottis), subglottis (sub- + glottis → below the glottis), and rima glottidis (rima = “cleft/opening” + glottidis = genitive of glottis → “opening of the glottis”). The related root gloss- / glott- also appears in non-laryngeal medical terms including glossitis, hypoglossal, glossopharyngeal, and polyglot.
🔀 ALIASES / ALTERNATE TERMS
Glottic(adjective form — used clinically in “glottic carcinoma,” “glottic insufficiency,” “glottic stenosis,” and “glottic web”)
True vocal cords(lay and clinical synonym for the vocal fold component of the glottis — distinguished from the false vocal cords/vestibular folds, which are part of the supraglottis)
Vocal folds(preferred modern anatomical term over “vocal cords”; used in all current laryngology, voice, and SLP literature; same structure, updated terminology)
Rima glottidis(the opening/cleft between the two true vocal folds; subdivided into the intermembranous part anteriorly between the vocal ligaments and the intercartilaginous part posteriorly between the arytenoid cartilages)
Glottic carcinoma(squamous cell carcinoma of the true vocal folds; the most common subsite of laryngeal cancer overall; excellent prognosis due to early hoarseness symptom and sparse lymphatic supply; C32.0)
Vocal cord paralysis(loss of vocal fold movement due to recurrent laryngeal nerve or vagal injury; unilateral J38.01, bilateral J38.02; causes breathy dysphonia, aspiration, and potential airway compromise)
Glottic insufficiency(incomplete glottal closure during phonation resulting in a breathy or weak voice; most common cause is vocal fold paralysis or atrophy/presbylaryngis; treated with injection laryngoplasty CPT 31570/31574 or medialization thyroplasty CPT 31591)
Vocal cord nodules(bilateral symmetric fibrous lesions at the mid-membranous vocal fold junction; the “singer’s nodes” / “screamer’s nodes”; coded to J38.2)
Vocal cord polyp(unilateral benign lesion of the vocal fold, often hemorrhagic or edematous; coded to J38.1; includes Reinke’s edema)
Vocal cord granuloma(posterior glottic contact granuloma at the vocal process of the arytenoid; commonly associated with LPR/GERD or intubation trauma; coded to J38.3)
Glottic web(abnormal fibrous band connecting the anterior vocal folds; congenital Q31.0 or acquired post-surgical/traumatic; causes variable degrees of dysphonia and airway compromise)
Presbylaryngis(age-related vocal fold atrophy and bowing causing glottic insufficiency and weak/breathy voice; coded to J38.3 — other diseases of vocal cords)
🔗 RELATED TERMS
supraglottis — the laryngeal compartment immediately above the glottis; includes the epiglottis, false vocal cords, aryepiglottic folds, and laryngeal ventricles; malignancy here coded to C32.1; see supraglottis note
Subglottis — the laryngeal compartment immediately below the glottis, extending from the inferior vocal cord surface to the inferior cricoid border; malignancy coded to C32.2; see Subglottis note
Recurrent laryngeal nerve (RLN) — the branch of the vagus nerve (CN X) that provides motor innervation to all intrinsic laryngeal muscles except the cricothyroid; RLN injury is the most common cause of unilateral vocal cord paralysis (J38.01) and is the nerve most at risk during thyroid/parathyroid surgery, anterior cervical spine procedures, and thoracic surgery
Arytenoid cartilages — the paired posterior cartilages whose rotational movement at the cricoarytenoid joints abducts and adducts the vocal folds; arytenoid subluxation or fixation post-intubation is a common cause of glottic dysfunction and dysphonia, coded to J38.3 or M26.69 depending on documentation
Cricothyroid muscle — the only intrinsic laryngeal muscle innervated by the superior laryngeal nerve (external branch) rather than the RLN; it stretches and tenses the vocal folds to raise pitch; injury causes pitch instability and is coded to J38.3
Dysphonia — the primary symptom of glottic pathology; hoarseness or voice change arising from abnormal vocal fold vibration; coded to R49.0; persistent dysphonia > 2 weeks should trigger laryngoscopic evaluation and may prompt a provider query on inpatient profee claims
Aphonia — complete loss of voice; represents severe glottic dysfunction (complete paralysis, surgical absence, or functional origin); coded to R49.1
laryngoscopy — the fundamental diagnostic and operative tool for glottic assessment; rigid direct and flexible fiberoptic variants cover CPT codes 31513-31591 for the glottic region
Laryngomalacia — primarily a supraglottic condition, but severe cases can functionally affect the glottic inlet; see supraglottis note; coded to Q31.5
Aspiration — entry of food/liquid into the airway below the glottis when glottic closure is incomplete; a major functional consequence of vocal cord paralysis and glottic incompetence; coded to J69.0 (aspiration pneumonitis) when aspiration results in pulmonary disease
Spasmodic dysphonia — a focal laryngeal dystonia causing involuntary spasms of the vocal folds during phonation; adductor type (voice breaks on vowels) is most common; treated with botulinum toxin injection to the vocal fold/thyroarytenoid muscle; coded to G24.4 (idiopathic orofacial dystonia) — NOT a J38 code; injected via CPT 31573 (flexible) or 64617 (percutaneous)
Other diseases of vocal cords — includes vocal cord granuloma, contact ulcer, presbylaryngis, leukoplakia of vocal cord, pachydermia laryngis, singer’s nodule not elsewhere classified
J38.4
Edema of larynx — includes edema of vocal fold; may occur post-intubation or in angioedema
Congenital Glottic Anomalies
Code
Description
Q31.0
Web of larynx — includes congenital glottic web; anterior commissure fibrous band; variable severity from mild dysphonia to significant obstruction
Q31.8
Other congenital malformations of larynx — includes congenital glottic stenosis not elsewhere classified
Laryngoscopy, flexible or rigid telescopic, with stroboscopy — gold standard for vocal fold vibratory assessment; essential for diagnosing subtle glottic lesions and dysphonia etiology
Laryngoscopy, direct, operative, with biopsy; with operating microscope or telescope — preferred for glottic tumor biopsy
31540
Laryngoscopy, direct, operative, with excision of tumor and/or stripping of vocal cords or epiglottis
31541
Laryngoscopy, direct, operative, with excision of tumor and/or stripping of vocal cords or epiglottis; with operating microscope or telescope — used for glottic carcinoma excision/cordectomy
31545
Laryngoscopy, direct, operative, with operating microscope or telescope, with submucosal removal of non-neoplastic lesion(s) of vocal cord; reconstruction with local tissue flap(s) — for vocal fold lesion with flap reconstruction (unilateral; may be billed twice)
31546
Laryngoscopy, direct, operative, with submucosal removal of non-neoplastic lesion(s) of vocal cord; reconstruction with graft(s) — includes obtaining autograft (unilateral; may be billed twice)
31570
Laryngoscopy, direct, with injection into vocal cord(s), therapeutic — vocal fold augmentation/injection laryngoplasty via rigid direct scope (OR setting)
31571
Laryngoscopy, direct, with injection into vocal cord(s), therapeutic; with operating microscope or telescope
Laryngoscopy, flexible; with therapeutic injection(s) (e.g., chemodenervation agent, corticosteroid), unilateral — used for botulinum toxin injection via flexible scope for spasmodic dysphonia
Laryngoplasty, medialization, unilateral — Type I thyroplasty; gold-standard open surgical treatment for unilateral vocal fold paralysis; implant placed via external neck incision to medialize the paralyzed fold
Chemodenervation of larynx; EMG-guided injection into intrinsic laryngeal muscle(s) — percutaneous botulinum toxin injection for spasmodic dysphonia (adductor type); report separately from laryngoscopy
⚠️ Coding Note: The glottis is the most symptom-early and prognosis-favorable laryngeal subsite for carcinoma, but accurate inpatient profee coding requires provider documentation of the specific subsite — “laryngeal cancer” defaults to C32.9 (unspecified), which carries different staging and DRG implications than C32.0 (glottis); always query if subsite is not explicitly documented. For vocal cord paralysis, laterality is required — J38.01 (unilateral) and J38.02 (bilateral) are not interchangeable; bilateral paralysis is a potential airway emergency with significantly higher DRG weight and acuity, and if a patient post-thyroidectomy has a weak/breathy voice, a provider query for unilateral vocal cord paralysis should be placed if not documented.
On inpatient profee claims, watch for documentation triggers like “hoarseness post-thyroidectomy,” “failed extubation,” “breathy voice,” “aspiration,” or “dysphonia” — these should prompt queries for vocal cord paralysis (J38.01/J38.02) or glottic stenosis (J38.6), both of which are frequently undercoded. For CPT coding, 31570/31571 (direct scope injection) are used in the OR under sedation/general anesthesia, while 31574 is specifically for in-office flexible scope injection augmentation — payers treat these differently for place-of-service and facility fee purposes; they are NOT interchangeable. 31545 and 31546 are each defined as unilateral procedures and may be reported twice (once per side) in the same operative session when bilateral vocal fold work is performed — append modifier -50 or report with the appropriate left/right modifier per payer preference.
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