1 Anatomy and function of the larynx

The larynx is a complex airway structure located in the anterior neck between the pharynx and trachea. It serves as a valve for breathing, protects the lower airway during swallowing, and houses the vocal folds, which generate sound during phonation. Because of these multiple roles, even modest structural or functional changes can produce noticeable symptoms.

1.1 Laryngeal cartilages and framework

The laryngeal framework is formed by several cartilages, including the thyroid, cricoid, epiglottic, arytenoid, corniculate, and cuneiform cartilages. These elements are connected by membranes, joints, and ligaments that permit movement of the vocal folds and adjustment of airway caliber. The framework provides both support and flexibility.

1.2 Vocal folds and glottic structures

The vocal folds are paired mucosal folds that extend from the thyroid cartilage anteriorly to the arytenoid cartilages posteriorly. The glottis refers to the space between them. Their layered composition allows vibration, while the surrounding muscles regulate tension, length, and closure. Small changes in this system can alter voice quality and airway function.

1.3 Innervation and blood supply

Motor innervation is primarily supplied by branches of the vagus nerve, especially the recurrent laryngeal nerve and the superior laryngeal nerve. These nerves control most intrinsic laryngeal muscles and contribute to sensation in the larynx. Blood supply comes mainly from the superior and inferior laryngeal arteries. Neurologic or vascular disturbance in these pathways may affect voice, breathing, and swallowing.

1.4 Role in respiration, phonation, and swallowing

During breathing, the larynx remains open to allow airflow. For speech, the vocal folds approximate and vibrate as air passes through them, producing sound. During swallowing, the larynx elevates and closes to help direct food and liquid away from the trachea. This coordinated activity is essential for airway protection and efficient communication.

2 Causes and classification

Laryngeal pathology includes a broad range of disorders with different causes and patterns of presentation. Conditions may be short-lived or chronic, mild or life-threatening, and they are often grouped by underlying mechanism. Classification helps guide evaluation and treatment.

2.1 Inflammatory conditions

Inflammatory disorders arise from irritation, allergy, reflux, environmental exposure, or autoimmune processes. They may cause mucosal swelling, redness, pain, and voice change. Some are acute and self-limited, while others persist because of repeated exposure or ongoing irritation.

2.2 Infectious conditions

Infections of the larynx are less common than those of adjacent upper airway structures but may occur with viral, bacterial, or fungal causes. They can present with hoarseness, fever, throat pain, or swelling. Certain infections may be associated with airway narrowing and require urgent attention.

2.3 Structural abnormalities

Structural disorders include benign lesions, scarring, stenosis, webs, and developmental abnormalities. These conditions may alter the shape or mobility of the larynx. Symptoms often depend on the site and extent of the abnormality, with voice change and breathing difficulty being common.

2.4 Traumatic injury

Trauma may result from blunt neck injury, penetrating wounds, inhalational injury, foreign bodies, or medical procedures. Damage can involve cartilage, mucosa, or soft tissues. Injury may lead to pain, swelling, hemorrhage, and impaired airway stability.

2.5 Neoplastic disease

Neoplastic disorders include benign and malignant tumors of the larynx. Benign growths may affect the vocal folds and voice quality, while malignant lesions can invade local tissues and obstruct the airway. Early evaluation is important when symptoms persist or progress.

2.6 Neuromuscular and functional disorders

Neuromuscular disorders result from impaired nerve supply or muscle control, leading to reduced motion or abnormal closure of the vocal folds. Functional disorders occur when laryngeal behavior is altered without a clear structural lesion, often influenced by vocal habits, stress, or compensatory muscle activity.

2.7 Congenital disorders

Congenital laryngeal disorders are present at birth and may involve malformations, incomplete development, or abnormal motion of the vocal folds. These conditions often become apparent in infancy or early childhood through noisy breathing, feeding difficulty, or weak cry.

3 Signs and symptoms

Clinical manifestations vary widely according to the location and severity of the disorder. Some patients present with isolated voice changes, while others develop airway compromise or swallowing dysfunction. Symptom patterns often provide important clues to the underlying cause.

3.1 Hoarseness and voice change

Hoarseness is one of the most common signs of laryngeal disease. Voice may sound rough, breathy, weak, strained, or intermittently broken. Changes in pitch, loudness, and vocal endurance may also occur, especially when the vocal folds cannot close or vibrate normally.

3.2 Stridor and breathing difficulty

Stridor is a high-pitched sound caused by turbulent airflow through a narrowed upper airway. It may be inspiratory, expiratory, or biphasic depending on the level of obstruction. Dyspnea, shortness of breath, and a sense of throat tightness may accompany it.

3.3 Throat pain and discomfort

Pain or irritation may arise from inflammation, infection, trauma, or mucosal lesions. Patients may describe burning, scratchiness, pressure, or a foreign-body sensation. The discomfort can worsen with speaking, swallowing, or coughing.

3.4 Dysphagia and aspiration

Swallowing difficulty may occur when the larynx fails to protect the airway adequately. Aspiration refers to entry of food, liquid, or secretions into the trachea. These problems may lead to coughing during meals, choking episodes, or recurrent lower respiratory infections.

3.5 Cough and throat clearing

Chronic cough and frequent throat clearing are common nonspecific symptoms. They may reflect irritation, secretion retention, reflux, or hyperfunctional voice use. In some cases, these behaviors themselves contribute to further laryngeal irritation.

3.6 Voice fatigue

Voice fatigue is a reduced ability to sustain normal vocal use over time. Patients may notice that the voice worsens with prolonged speaking and improves with rest. This symptom is often seen in inflammatory, structural, and functional disorders.

4 Diagnostic evaluation

Diagnosis relies on correlating symptoms with direct visualization and targeted testing. The choice of studies depends on whether the main concern is voice change, airway compromise, swallowing impairment, or suspected mass lesion. A stepwise approach is commonly used.

4.1 Medical history and physical examination

History should address symptom duration, onset, triggers, vocal use, smoking or irritant exposure, reflux symptoms, trauma, prior surgery, and neurologic disease. Examination includes assessment of the mouth, neck, breathing pattern, and general neurologic status. Stridor, neck tenderness, and voice quality may provide important clues.

4.2 Flexible laryngoscopy

Flexible laryngoscopy allows direct visualization of the larynx during spontaneous breathing and phonation. It is a central tool for identifying inflammation, lesions, asymmetry, impaired motion, and airway narrowing. The procedure is usually performed in an outpatient setting.

4.3 Stroboscopy

Stroboscopy uses flashing light to assess vocal fold vibration during speech. It reveals subtle abnormalities in mucosal wave, closure pattern, symmetry, and periodicity that may not be visible on ordinary examination. This method is especially valuable in voice disorders.

4.4 Imaging studies

Imaging is useful when deeper tissue involvement, cartilage injury, mass effect, or extralaryngeal extension is suspected. It complements endoscopic assessment and helps define the extent of structural disease.

4.4.1 CT scan

Computed tomography is helpful for evaluating fractures, calcified structures, airway narrowing, and some tumors. It provides detailed anatomic information and is often used when trauma or a mass lesion is suspected. Contrast may improve assessment of soft tissue extent.

4.4.2 MRI

Magnetic resonance imaging offers superior soft tissue contrast and may aid in assessing tumor spread, deep soft tissue injury, or complex congenital anomalies. It is less useful than CT for fine bony detail but can be valuable in selected cases.

4.5 Voice assessment

Voice assessment may include perceptual evaluation, acoustic analysis, aerodynamic testing, and patient-reported outcome measures. These tools quantify severity and help monitor response to treatment. They are particularly useful in chronic and functional voice disorders.

4.6 Biopsy and histopathology

Biopsy is performed when a lesion appears suspicious for dysplasia or malignancy, or when the diagnosis remains uncertain after endoscopic examination. Histopathologic analysis identifies tissue type, degree of atypia, inflammation, infection, or invasion. Sampling is often done during microlaryngoscopy.

4.7 Swallow evaluation

Swallow assessment may include bedside examination, videofluoroscopic swallow study, or endoscopic swallow testing. These studies help detect aspiration, residue, and impaired laryngeal closure. They are particularly important in neurologic disease, structural abnormalities, and postsurgical patients.

5 Inflammatory and infectious disorders

Inflammatory and infectious conditions are common causes of laryngeal symptoms. They often produce hoarseness, throat irritation, and cough, though severe edema or supraglottic infection may threaten the airway. Management depends on cause, severity, and duration.

5.1 Acute laryngitis

Acute laryngitis is a short-term inflammation of the laryngeal mucosa, often associated with viral upper respiratory illness or vocal overuse. Hoarseness is typical, and the voice may become weak or absent. Rest, hydration, and avoidance of irritants are often beneficial.

5.2 Chronic laryngitis

Chronic laryngitis reflects persistent inflammation, which may result from smoking, reflux, chronic vocal strain, environmental exposure, or recurrent infection. Symptoms usually develop gradually and may include ongoing hoarseness, throat clearing, and a sensation of irritation. Prolonged inflammation can contribute to tissue change.

Reflux-related laryngeal irritation occurs when gastric contents reach the laryngopharynx and irritate laryngeal tissues. Patients may report globus sensation, cough, hoarseness, or throat clearing rather than classic heartburn. Because symptoms are nonspecific, careful assessment is needed before attributing complaints solely to reflux.

5.4 Laryngeal edema

Laryngeal edema is swelling of the laryngeal tissues that may result from infection, allergy, trauma, inhalation injury, or prolonged irritation. Mild swelling can cause hoarseness, whereas severe edema may narrow the airway. Rapid progression requires urgent evaluation.

5.5 Epiglottic and supraglottic infections

Infections involving the epiglottis and supraglottic structures are clinically significant because of the risk of sudden airway obstruction. Patients may have fever, severe throat pain, drooling, muffled voice, and difficulty breathing or swallowing. These conditions often require prompt medical treatment and close airway monitoring.

6 Benign structural lesions

Benign lesions of the vocal folds commonly arise from repeated mechanical stress, chronic irritation, or localized tissue change. They often affect voice quality more than breathing, though larger lesions can interfere with airflow or swallowing. Treatment is tailored to lesion type and severity.

6.1 Vocal fold nodules

Vocal fold nodules are bilateral, callus-like thickenings that usually develop near the midpoint of the vocal folds. They are associated with repetitive vocal strain and are common in people with heavy voice use. Hoarseness and vocal fatigue are typical.

6.2 Vocal fold polyps

Vocal fold polyps are often unilateral and may be soft, vascular, or gelatinous. They can arise after acute or chronic phonotrauma. Patients may notice sudden voice change, breathiness, or reduced vocal range.

6.3 Vocal fold cysts

Vocal fold cysts are encapsulated lesions within or beneath the vocal fold surface. They may be mucus retention cysts or epidermoid-type lesions. Because they alter vibratory motion, they often produce persistent hoarseness that does not fully resolve with rest alone.

6.4 Reinke edema

Reinke edema is swelling of the superficial layer of the vocal fold, producing a bulky, flexible appearance. It is often linked to smoking and chronic irritation. The voice may become deep, rough, and low pitched, and advanced cases can affect breathing.

6.5 Granulomas

Laryngeal granulomas are inflammatory masses, usually located on the posterior vocal folds. They may develop after intubation, reflux, or repeated throat clearing. Symptoms include throat discomfort, hoarseness, and a sensation of something being stuck in the throat.

6.6 Papillomas

Papillomas are benign epithelial growths caused by human papillomavirus infection. They may appear as multiple wart-like lesions on the larynx and can recur after treatment. Depending on size and number, they may lead to hoarseness, stridor, or airway obstruction.

7 Neurologic and functional disorders

Disorders of laryngeal motion can result from nerve injury, central neurologic disease, altered muscle coordination, or maladaptive voice use. These conditions often produce complex symptoms that require careful distinction from structural disease.

7.1 Vocal fold paralysis

Vocal fold paralysis refers to complete loss of movement in one or both vocal folds, usually due to nerve dysfunction. Unilateral paralysis often causes breathy voice and weak cough, while bilateral paralysis may create significant airway compromise. Causes include surgery, tumors, inflammation, and neurologic disease.

7.2 Vocal fold paresis

Paresis is partial weakness rather than complete immobility of the vocal fold. It may produce subtle hoarseness, vocal fatigue, or difficulty projecting the voice. Diagnosis can be challenging because the abnormality may be mild and intermittent.

7.3 Spasmodic dysphonia

Spasmodic dysphonia is a focal dystonia affecting laryngeal muscle control during speech. It causes involuntary voice breaks, strain, or intermittent voice interruption. Symptoms usually worsen during speaking and may improve during laughter, whispering, or singing.

7.4 Muscle tension dysphonia

Muscle tension dysphonia is a functional voice disorder in which excessive or inappropriate laryngeal and neck muscle activity disrupts normal phonation. Patients may sound strained, pressed, or effortful. It frequently develops as a compensatory pattern after irritation or vocal overload.

7.5 Paradoxical vocal fold motion

Paradoxical vocal fold motion involves inappropriate closure of the vocal folds during inspiration, leading to episodic breathing difficulty and stridor. It may resemble asthma but originates at the laryngeal level. Episodes can be triggered by exercise, irritants, stress, or reflux.

8 Traumatic and iatrogenic injuries

Laryngeal injury can follow external force, inhalation of harmful substances, instrumentation, or repeated vocal stress. The effects range from minor mucosal damage to fractures, scarring, and chronic dysfunction. Prompt recognition is important when airway stability is in question.

8.1 External laryngeal trauma

External trauma includes blunt or penetrating injury to the neck. It may cause pain, swelling, bruising, airway compromise, or cartilage fracture. Severe cases can threaten breathing and require emergency intervention.

8.2 Internal laryngeal injury

Internal injury may result from inhaled heat, chemicals, foreign bodies, or direct mucosal damage. Symptoms vary from temporary hoarseness to significant edema and scarring. Depth of injury determines the likelihood of long-term impairment.

Endotracheal intubation can cause mucosal abrasion, ulceration, granuloma, edema, or joint fixation if the larynx is exposed to prolonged pressure or repeated trauma. Patients may develop hoarseness, sore throat, or breathing changes after the procedure. Most cases are mild, but some lead to persistent dysfunction.

8.4 Voice overuse and phonotrauma

Repeated excessive voice use can injure the vocal folds through mechanical stress. This may contribute to nodules, polyps, hemorrhage, and chronic swelling. Teachers, singers, call-center workers, and others with heavy vocal demands are at increased risk.

9 Malignant and premalignant lesions

Premalignant and malignant laryngeal lesions often present with persistent hoarseness, throat symptoms, or airway changes. Because early-stage disease may be subtle, persistent voice alteration warrants careful assessment. Tissue diagnosis is essential when cancer is suspected.

9.1 Laryngeal dysplasia

Laryngeal dysplasia is a premalignant epithelial change that ranges from mild cellular abnormality to severe atypia. It may develop in the setting of chronic irritation or tobacco exposure. Dysplasia is important because it can progress to invasive carcinoma in some cases.

9.2 Squamous cell carcinoma

Squamous cell carcinoma is the most common malignant tumor of the larynx. It arises from the surface epithelium and may involve different laryngeal subsites. Presentation depends on location and extent, ranging from isolated hoarseness to airway symptoms and swallowing difficulty.

9.3 Supraglottic carcinoma

Supraglottic carcinoma affects the structures above the true vocal folds, including the epiglottis and aryepiglottic folds. It may present later than glottic disease because early voice change is less prominent. Symptoms can include throat pain, lump sensation, dysphagia, and neck mass.

9.4 Glottic carcinoma

Glottic carcinoma arises from the true vocal folds and commonly causes early hoarseness because the lesion directly affects phonation. This symptom often prompts earlier evaluation than in other laryngeal subsites. Airway symptoms may appear as the lesion enlarges.

9.5 Subglottic carcinoma

Subglottic carcinoma occurs below the vocal folds and may remain hidden longer because voice symptoms can be less obvious initially. Patients may instead develop breathing difficulty or cough. Detection may be delayed until the lesion has grown.

10 Congenital and pediatric disorders

Laryngeal disorders in infants and children often present differently from adult disease. Noisy breathing, feeding difficulty, weak cry, and poor weight gain are common concerns. Evaluation must account for developmental anatomy and the higher sensitivity of the pediatric airway.

10.1 Laryngeal web

A laryngeal web is a membrane-like band of tissue that partially bridges the laryngeal airway, usually near the vocal folds. It may be congenital or acquired. Severity determines whether the main issue is hoarseness, stridor, or significant airway narrowing.

10.2 Laryngomalacia

Laryngomalacia is the most common cause of noisy breathing in infants and results from flaccid supraglottic tissues that collapse inward during inspiration. Symptoms usually worsen with feeding, crying, or lying supine. Many cases improve with growth, though some require intervention.

10.3 Subglottic stenosis

Subglottic stenosis is narrowing below the vocal folds, often due to congenital development or acquired scarring. It can produce stridor, retracted breathing, and difficulty tolerating respiratory illness. Severity varies from mild narrowing to critical obstruction.

10.4 Congenital vocal fold paralysis

Congenital vocal fold paralysis is present at birth and may be unilateral or bilateral. It can cause weak cry, aspiration, or respiratory distress. Associated neurologic or developmental conditions may also be present.

10.5 Pediatric papillomatosis

Pediatric papillomatosis refers to recurrent papillomas of the larynx in children. It often causes persistent hoarseness and, in more extensive cases, noisy breathing. The course is typically chronic and may require repeated treatment because of recurrence.

11 Treatment and management

Management depends on the cause, severity, and functional impact of the disorder. Some conditions respond to conservative measures, while others require procedural intervention or long-term surveillance. Treatment often combines medical care, voice rehabilitation, and surgery when needed.

11.1 Medical therapy

Medical treatment targets infection, inflammation, reflux, swelling, and contributing conditions. It is frequently used early in the course of disease or alongside procedural management. Appropriate therapy depends on a specific diagnosis rather than symptoms alone.

11.1.1 Antibiotics and antivirals

Antimicrobial therapy is reserved for selected bacterial or viral infections when a pathogen or clinical syndrome supports its use. Not all laryngeal inflammation requires these drugs. Supportive care is often sufficient for uncomplicated viral illness.

11.1.1.1 Indications and limitations

Use of antibiotics and antivirals depends on suspected organism, severity, and host factors. These agents may be ineffective when symptoms stem from reflux, strain, allergy, or noninfectious inflammation. Overuse can delay correct diagnosis and expose patients to unnecessary side effects.

11.1.2 Anti-inflammatory therapy

Anti-inflammatory medication may be used to reduce edema and discomfort in selected cases. Corticosteroids are sometimes considered when swelling threatens the airway or significantly impairs function. Their use is guided by the underlying cause and clinical urgency.

11.1.3 Reflux management

Reflux management includes dietary modification, behavioral changes, and medication when indicated. Measures may involve avoiding late meals, reducing irritants, and elevating the head of the bed. Because reflux symptoms are nonspecific, treatment is most effective when paired with careful clinical assessment.

11.2 Voice therapy and rehabilitation

Voice therapy helps patients improve vocal technique, reduce strain, and restore efficient phonation. It is especially useful for nodules, muscle tension dysphonia, recovery after injury, and some cases of paresis or paralysis. Rehabilitation may also include breathing strategies and counseling on vocal hygiene.

11.3 Surgical management

Surgery is used when a lesion, airway obstruction, structural defect, or suspicious mass requires direct correction. The approach depends on diagnosis, location, and functional goals. Preservation of voice and airway is often a major objective.

11.3.1 Microlaryngoscopy

Microlaryngoscopy provides magnified access to the larynx for detailed examination and treatment. It allows precise manipulation of vocal fold lesions while limiting surrounding tissue trauma. The technique is widely used for diagnosis and surgery.

11.3.2 Lesion excision

Excision may be performed for benign lesions, papillomas, dysplastic tissue, or selected tumors. The goal is complete or partial removal while conserving healthy mucosa whenever possible. Postoperative voice care is often important.

11.3.3 Airway procedures

Airway procedures include tracheostomy, dilation, reconstruction, and other operations used to secure or enlarge the airway. They are considered when obstruction is severe or expected to persist. The choice of procedure depends on the site and cause of narrowing.

11.4 Airway support and emergency care

Urgent management is required when laryngeal disease causes significant obstruction, respiratory distress, or rapidly worsening swelling. Supportive care may include oxygen, airway monitoring, positioning, and escalation to advanced airway intervention. Safety of the airway takes priority over definitive diagnosis in emergencies.

11.5 Follow-up and surveillance

Follow-up is important because many laryngeal disorders recur, evolve, or require monitoring for response to treatment. Surveillance may include repeat laryngoscopy, symptom review, voice testing, or imaging when indicated. Long-term observation is especially relevant for dysplasia, papillomatosis, and chronic functional disorders.

12 Complications and prognosis

Outcomes vary from complete recovery to persistent voice or airway impairment. Prognosis depends on etiology, timeliness of diagnosis, extent of tissue damage, and response to treatment. Some conditions are self-limited, while others need ongoing management.

12.1 Airway obstruction

Airway obstruction is the most urgent complication of laryngeal disease. It may develop from edema, infection, trauma, tumors, bilateral vocal fold immobility, or congenital narrowing. Severity ranges from mild exertional symptoms to respiratory failure.

12.2 Aspiration pneumonia

When laryngeal closure is impaired, material may enter the lungs and cause aspiration pneumonia. This complication is more likely in patients with swallowing dysfunction, neurologic disease, or structural abnormalities. Recurrent aspiration can substantially affect health and recovery.

12.3 Chronic voice impairment

Persistent dysphonia may remain after inflammation, lesion removal, nerve injury, or functional disorder. Voice changes can interfere with communication and occupational performance. Rehabilitation may improve outcome, but recovery is not always complete.

12.4 Recurrence and malignant transformation

Some benign and premalignant lesions can recur after treatment, particularly when the underlying cause persists. Dysplastic lesions may progress toward cancer in a subset of cases, making surveillance important. Recurrence risk varies by pathology and treatment adequacy.

12.5 Functional outcomes and quality of life

Laryngeal pathology may affect speech, breathing, swallowing, social interaction, and work capacity. Even non-life-threatening disorders can significantly reduce quality of life when symptoms are chronic. Effective management aims not only to restore anatomy, but also to improve daily function and patient well-being.