What are the possible side effects of treatments for voice disorders?

Depends on cause. Side effects of treatments for voice disorders depends on the cause of the voice problem. If there is not cyst, nodule or other mass, nerve of brain dysfunction causing the voice disorder, it is treated with speech therapy.
Depends on treatment. There is a great deal of variety to voice disorders. There are neurological causes (nerve weakness, etc.), structural causes (masses/polyps/nodules/scarring), allergic causes, reflux, as well as other causes that can affect your voice. Treatment include voice therapy, local medication, injections, and surgery. And side effects really depend on the treatment.

Related Questions

What are the treatments for voice disorders?

Different treatments. Voice disorders include many problems, so a short answer isn't possible. In very broad terms, depending on the problem, treatments may include medications, voice therapy and lifestyle modifications, vocal exercises, or surgery. If you have a voice problem, seek out an ent/laryngologist, especially if you have a profession which relies on your voice. Best wishes.
Many treatments. There is a great deal of variety of voice disorders. There are neurological causes (nerve weakness, etc.), structural causes (masses/polyps/nodules/scarring), allergy as well as other causes that can affect your voice. If you suspect a voice issue, seeing a specialist early is important to find the cause and treat it appropriately. Treatment include therapy, local medication, injections, surgery.