The atlantoaxial joint is located just below the skull and at the top of the cervical spine. Atlantoaxial subluxation is a condition in which the normal position of the atlantoaxial joint is misaligned by external force, injury, infection, etc., and stimulates or compresses the local nerves, blood vessels, and muscles, resulting in corresponding symptoms, and is accompanied by limited cervical movement. To recognize atlantoaxial subluxation, we must first understand the structure and function of the atlantoaxial joint. As you know, the head is the center of life, and it is high on the top of the cervical spine. The occipital foramen below the skull has an extension of the brain, through which the medulla oblongata, carotid artery, jugular vein, and vertebral artery pass, which is an important part of life. Directly connected to the foramen is the first vertebra of the cervical spine, the “atlas”, and the second vertebra, the “cardinal vertebra”. Both of these vertebrae are called special vertebrae because of their peculiar shapes and special physiological tasks. The first cervical vertebra is the atlantoaxial vertebra, which consists of two arches and two lateral blocks interconnected into a ring, which becomes articulated with the condyles of the occipital bone and articulates with the second vertebra, the pivot vertebra. The pivotal vertebra has a columnar protrusion centered on the vertebral body that forms a rotatable joint with the peripheral atlas, hence the name pivotal vertebra. The special structure of the atlantoaxial and pivotal vertebrae allows the head to rotate left and right and to move laterally, and if misalignment occurs, it will directly affect the movement of the head and prevent the head from turning to speak to people, and if necessary, the body will need to turn together. Since the vertebral artery and nerve trunk of the neck have to pass through this important barrier, a misalignment of the atlantoaxial joint directly affects the vascular nerves entering the skull and brain, and a series of unbearable painful symptoms such as dizziness, nausea, sudden fall, irritability, migraine, and stiff neck soon appear. At this time, due to the fierce pressure of the disease many people panic like to make brain CT or check the heart, infusion and injection emergency, although the symptoms are alleviated, but tossed to the end still can not cure the disease. Therefore, it is necessary to correctly understand the disease of atlantoaxial joint dislocation, and go to a specialist in a timely manner, so that the pain can be relieved from the root as soon as possible and the harm caused to the human body can be minimized. The atlanto-axial joint plays the role of the top and bottom of the head, connecting the skull and trunk, not only supporting the head, but also providing a good range of motion of the head. The atlantoaxial joint is primarily rotational, accounting for half of the movement of the entire cervical spine, and is normally accompanied by a range of horizontal movement from left to right and back to front. Most of the range of motion of the head and the visual range of the eyes is also achieved primarily by the movement of the atlantoaxial joint. The atlantoaxial joint has a three-dimensional, three-directional mode of motion; the left-right rotational motion provides the ability to rotate the head left and right up to 45º, increasing the visual range of the eyes; the up-and-down and left-right lateral flexion of the atlas increases the range of motion of the head and has played a role in human evolution. The specific results of the atlantoaxial joint also protect the local spinal cord from external forces and also protect the vertebral arteries entering the cranial segment.