Vocal Cord Polyp
Polyps originate on the surface of the vocal cords usually after some degree of trauma. Your polyp may have originated from a vocal cord hemorrhage at one point from excessive yelling, inefficient singing, or other vocal abuse. Alternatively it may have arisen from trauma from an endotracheal tube intubation or other airway irritant.
If the polyp is small enough, it may resolve on its own with conservative treatment (voice therapy, avoidance of vocal abuse, management of acid reflux, etc.). Often, however, it is best treated with surgery to remove the polyp. Voice rest is required after surgery for one week while the vocal cord heals.