The recurrent laryngeal nerve is one of the two main nerves in the larynx and is the main motor nerve, the other being the superior laryngeal nerve. The recurrent laryngeal nerve is derived from the vagus nerve. The recurrent laryngeal nerve is divided into the left side and the right side, and the left recurrent laryngeal nerve generally crosses the aorta and then returns. That’s why it’s called the recurrent laryngeal nerve, which returns to the larynx. Because it is the aortic arch, it crosses the aortic arch and has a longer path of travel. And the right reflex returns to the fat before the subclavian artery returns to the larynx. The pathway is shorter, so clinically the pathway is longer and the chance of damage is relatively high. Injuries to the recurrent laryngeal nerve such as diseases of the chest, lungs, thyroid gland, and the larynx itself. The damage affects the movement of the vocal cords and leads to laryngeal paralysis.