It is normal for both sides of the neck to bulge when speaking because it is related to the way the speaker speaks. When the speaker speaks in a more agitated manner, it can cause the carotid artery on both sides of the neck to become angry and the sternocleidomastoid muscle to thicken. If the unilateral neck bulge is considered to be caused by pharyngeal diverticulum when speaking, it is not normal for it to be a disease. A pharyngeal diverticulum is a pouch-like structure formed by the mucosa and submucosa of the pharynx that bulges outward. Pharyngeal diverticula may be associated with cricopharyngeal muscle and esophageal dysfunction and increased pressure in the pharyngeal cavity, and may be caused by weakness of the pharyngeal wall in older patients, or by congenital malformations in younger patients. Small pharyngeal diverticula can be asymptomatic or have symptoms of gastroesophageal reflux pharyngitis, such as larger pharyngeal diverticula can be swallowed or when shouting loudly, the neck can have a mass that expands and shrinks with the change of air pressure in the pharynx, and the mass can shrink with pressure.