Neck rattling can be caused by synovial fluid bubble rupture, ligament calcification and pseudo-dislocation of small joints. 1. Rupture of synovial fluid bubbles: When you shake your head from side to side, you can shake the synovial fluid in the cervical joints that contain soluble gases. Under the negative pressure of the joint cavity, the gases in the synovial fluid will be vaporized into bubbles, and when the pressure increases to a certain degree and the bubbles rupture, the neck will make a rattling sound. 2. Calcification of ligaments: The ligaments of the cervical vertebrae that are calcified will be pulled when the head is shaken from side to side, because the elasticity of the ligaments decreases and the hardness increases, so the neck will make a rattling sound. 3. Pseudo-dislocation of the small joints: Usually each vertebra behind the cervical vertebrae has two small joints in the shape of a stack of tiles, if the small joints are overactive when shaking the head from side to side, resulting in a pseudo-dislocation of the small joints, the neck will also produce a rattling sound. If you shake your head from side to side and your neck rattles, you should go to a regular hospital in time to find out the cause of the disease, and choose the appropriate method of treatment under the guidance of a professional doctor.