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Epidemiology
Dysphonia is a general term for voice impairment that is sometimes used synonymously with hoarseness. Hoarseness is a perceptual voice quality often associated with dysphonia. According to a review of the literature on hoarseness, it is the reason for 1% of all visits to primary care providers. Its lifetime prevalence among primary care patients is 30%. Since hoarseness is a symptom, it is associated with a number of laryngeal diagnoses. The most common causes of hoarseness is laryngitis (acute 42.1%; chronic 9.7%) and functional dysphonia (30%). Hoarseness can also be caused by laryngeal tumours (benign 10.7 - 31%; malignant 2.2 - 3.0%). Aetiologies that are overall less prevalent include neurogenic conditions (2.8 - 8.0%), psychogenic conditions (2.0 - 2.2%), and aging (2%).

There are sex and age differences associated with dysphonia. Higher rates of dysphonia are reported in females (1.2%). It is proposed that higher rates in females are due to anatomical differences of the vocal mechanism. However, in childhood dysphonia is more often found in boys than girls. The prevalence of dysphonia in children is 23.4%. The most common laryngeal diagnosis among children is vocal fold nodules, a condition known to be associated with vocally damaging behaviours. As there are no anatomical differences in larynges of boys and girls prior to puberty, it has been proposed that higher rates of voice impairment in boys arise from louder social activities, personality factors, or more frequent inappropriate vocal use. However, a review of the limited literature on pediatric dysphonia failed to establish these connections. Among the elderly, dysphonia is associated with changes to anatomy and physiology as part of the natural aging process. Higher rates of dysphonia are reported in people over the age of 70 (2.5%). Findings regarding the prevalence of geriatric dysphonia have very variable, ranging from 4 - 29.1%. This variability is likely due to different methodology used in obtaining information from participants. The lifetime prevalence of dysphonia among the elderly is 52.4% The most common laryngeal diagnoses among the elderly are polyps, laryngopharyngeal reflux, muscle tension dysphonia, vocal fold paresis or paralysis, vocal fold mass, glottic insufficiency, malignant lesions, and neurologic conditions affecting the larynx.

It has been suggested that certain occupational groups may be at increased risk of developing dysphonia. The risk of developing voice disorders among teachers and singers has been studied extensively. The risk of developing dysphonia is significantly higher among teachers, however the prevalence rate is highly variable for methodological reasons. Findings for prevalence among singers also varied from study to study, possibly due to differences in interpretation of what constitutes a "singer". The self-reported prevalence of dysphonia among singers is 47%.