The causes of the back of the neck protrusion are the following: first, physiological protrusion, that is, the backward extension of the spinous process of the cervical vertebrae, especially in people with a thin body type, when the head will be very obvious, no pain, no itch, usually no conscious symptoms, this is a normal phenomenon, no need to worry excessively. Second, the accumulation of fat in the neck, usually seen in more obese patients, when the fat accumulation in the back of the neck area will appear fatty growth, commonly known as rich bag, usually also appear the symptoms of neck discomfort. Third, the protrusion of the back of the neck should also be considered whether it is a tumor such as lipoma, it is recommended that patients go to the hospital in a timely manner, through ultrasound or other tests of the neck to further clarify the diagnosis.