These causes can range from vocal abuse and misuse to systemic diseases. Causes of dysphonia can be divided into five basic categories, although overlap may occur between categories. (Note that this list is not exhaustive):

Employment
It has been suggested that certain occupational groups may be at increased risk of developing dysphonia due to the excessive or intense vocal demands of their work. Research on this topic has primarily focused on teachers and singers, although some studies have examined other groups of heavy voice users (e.g. actors, cheerleaders, aerobic instructors, etc.). At present, it is known that teachers and singers are likely to report dysphonia. Moreover, physical education teachers, teachers in noisy environments, and those who habitually use a loud speaking voice are at increased risk. The term clergymans throat or dysphonia clericorum was previously used for painful dysphonia associated with public speaking, particularly among preachers. However, the exact prevalence rates for occupational voice users are unclear, as individual studies have varied widely in the methodologies used to obtain data (e.g. employing different operational definitions for "singer"). Mechanism
Located in the anterior portion of the neck is the larynx (also known as the voice box), a structure made up of several supporting cartilages and ligaments, which houses the vocal folds. In normal voice production, exhaled air moves out of the lungs and passes upward through the vocal tract. At the level of the larynx, the exhaled air causes the vocal folds to move toward the midline of the tract (a process called adduction).
A medical treatment involves the use of botulinum toxin (botox) or anti-reflux medicines, for example. Botox is a key treatment for voice disorders such as Spasmodic Dysphonia. Voice therapy is mainly used with patients who have an underlying cause of voice misuse or abuse. Laryngologists also recommend this type of treatment to patients who have an organic voice disorder - such as vocal fold nodules, cysts or polyps as well as to treat functional dysphonia. Certain surgical treatments can be implemented as well - phono microsurgery (removal of vocal fold lesions performed with a microscope), laryngeal framework surgery (the manipulation of the voice box), as well as injection augmentation (injection of substance to vocal folds to improve closure). Surgical treatments may be recommended for patients having an organic dysphonia.A combination of both an indirect treatment method (an approach used to change external factors affecting the vocal folds) and a direct treatment method (an approach used where the mechanisms functioning during the use of the vocal folds, such as phonation or respiration, are the main focus) may be used to treat dysphonia. Direct therapies
Direct therapies address the physical aspects of vocal production. Techniques work to either modify vocal fold contact, manage breathing patterns, and/or change the tension at level of the larynx. Notable techniques include, but are not limited to, the yawn-sigh method, optimal pitch, laryngeal manipulation, humming, the accent method, and the Lee Silverman Voice Treatment.