What causes dysphonia?

Causes of Dysphonia

Dysphonia results from a broad spectrum of etiologies ranging from benign self-limited conditions to life-threatening malignancies, with the most critical distinction being whether it represents a harbinger of head and neck cancer, neurologic disease, or iatrogenic injury versus common benign causes like voice overuse, muscle tension dysphonia, or viral laryngitis. 1

Life-Threatening and High-Morbidity Causes (Require Urgent Evaluation)

Malignancy

• Head and neck cancer is the most critical diagnosis to exclude, as delayed diagnosis results in higher staging, more aggressive treatment requirements, and reduced survival rates 1
• Smoking increases the odds of head and neck cancer 2- to 3-fold and is the strongest risk factor for malignancy 1
• Laryngeal cancer, lung cancer, and thyroid cancer can all present with dysphonia 1

Neurologic Conditions

• Vocal fold paralysis from various causes including stroke, tumors compressing the recurrent laryngeal nerve, or progressive neurologic disease 1, 2
• Spasmodic dysphonia and other laryngeal dystonias almost universally manifest with dysphonia 1, 3
• Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis, myasthenia gravis, and essential tremor 1
• Left recurrent laryngeal nerve paralysis is more common due to its longer anatomic path around the aortic arch 2

Iatrogenic/Traumatic Causes

• Post-surgical injury following thyroid surgery (up to 2.1% incidence), cervical anterior surgery (1.69-24.2%), or head/neck/chest procedures 1, 2
• Endotracheal intubation causes dysphonia in up to 94% of patients, with potential for vocal fold paralysis and aspiration 1, 2
• Laryngeal fracture, inhalational injury, and blunt/penetrating trauma 1

Common Benign Causes

Inflammatory/Infectious

• Acute viral laryngitis associated with upper respiratory tract infection is the most common cause and typically self-limited, resolving in 7-10 days 1
• Chronic laryngitis from various causes 1
• Fungal laryngitis from inhaled steroids, which must be distinguished from malignancy 1
• Candidiasis 1

Functional/Behavioral

• Voice overuse is perhaps the most common cause of chronic dysphonia, affecting >50% of teachers with 20% missing work as a result 1
• Muscle tension dysphonia (MTD) constitutes 10-40% of voice center caseloads and involves increased laryngeal musculoskeletal tension with excessive recruitment 1
• MTD can be primary (no identifiable laryngeal disorder) or secondary (occurring with other laryngeal pathology) 1
• Functional/psychogenic dysphonia and aphonia 1, 4

Structural Lesions

• Vocal fold nodules represent 77% of dysphonia causes in children, developing mainly from vocal abuse 2
• Vocal fold polyps and cysts 1
• Polypoid vocal fold lesions associated with smoking 1
• Laryngeal papilloma in children, which carries high potential for life-threatening airway obstruction 1

Systemic and Medication-Related Causes

Gastrointestinal

• Laryngopharyngeal reflux (LPR) and gastroesophageal reflux disease 1
• Eosinophilic esophagitis 1

Rheumatologic/Autoimmune

• Rheumatoid arthritis, Sjögren's syndrome, sarcoidosis, amyloidosis, granulomatosis with polyangiitis 1

Medication-Induced Dysphonia 1

• Inhaled steroids: dose-dependent mucosal irritation and fungal laryngitis
• ACE inhibitors: chronic cough leading to voice changes
• Antihistamines, diuretics, anticholinergics: drying effect on mucosa
• Coumadin, thrombolytics, phosphodiesterase-5 inhibitors: vocal fold hematoma
• Bisphosphonates: chemical laryngitis
• Testosterone, Danocrine: sex hormone alterations
• Antipsychotics: laryngeal dystonia

Endocrine/Hormonal

• Hypothyroidism and other endocrinopathies 1
• Testosterone deficiency 1
• Menopause 1

Age-Related

• Presbylarynx (age-related laryngeal changes) causes substantially higher prevalence in elderly, with 2.5% of those >70 years affected 1, 2

Pulmonary

• COPD and asthma (both from disease effect and inhaled steroid use) 1

High-Risk Populations Requiring Lower Threshold for Evaluation

• Professional voice users (singers, teachers, legal professionals, clergy, coaches) who cannot adequately perform required duties 1
• Smokers and alcohol users given 2-3 fold increased cancer risk 1
• Children (23.4% prevalence at some point, higher in boys aged 8-14) 1, 2
• Elderly patients (prevalence 1.3% in ages 60-69,2.5% in >70 years) 1

Critical Clinical Pitfall

The most dangerous error is failing to recognize dysphonia as a potential presenting symptom of head and neck cancer, particularly in smokers, as delayed laryngeal evaluation results in higher cancer staging and reduced survival. 1 Any patient with tobacco use, concurrent neck mass/lymphadenopathy, or dysphonia persisting beyond 4 weeks requires direct laryngeal visualization 1, 5.