8 months baby sleep bone joint ringing, may be the normal development of the situation does not matter, there may be a lack of calcium, joint dislocation and so on caused by the more important, need to take treatment. 1. Normal development: because the baby is relatively small, the joint ligaments are not fully developed firmly, the establishment of the joints is not good, if the baby sleeps because of postural changes, it is possible that the joints between the bone friction, resulting in the sound ringing, do not need special treatment. 2. Calcium deficiency: If the baby lacks calcium, it is easy to lead to abnormal bone development, which will cause the symptoms of sound when the joints are moving and accompanied by developmental delay, you need to give your baby calcium supplements in a timely manner, such as calcium lactate, calcium gluconate and so on. 3. joint dislocation: it is possible that the baby limbs joints dislocation will occur only a slight activity, there is a joint ringing sound, need to take timely manipulation or surgical reset. 8 months baby sleep bone joint ringing, if accompanied by other abnormal symptoms, should promptly take the baby to the hospital.