The cause of left side rib ectopia is the normal physiological development process of infants, but also may be congenital deformity, fracture, etc., need to be on the cause of drug or surgical treatment. 1. For infants caused by normal physiological development process, due to the baby’s respiratory abdominal movement amplitude is larger, the rib cage is softer in the case of rib ectopia can occur, with the development will gradually approach the normal. 2. For congenital deformity, if the deformity is mild and does not affect the work of normal organs, it can be left untreated; if the deformity is serious and has uncomfortable symptoms or affects the lung function, surgery should be considered to correct it. 3. For fractures, they should be reset and fixed, if the pain is serious, oral ibuprofen, morphine and other analgesics can be taken as prescribed by the doctor, and if blood vessels, nerves and organs are damaged, surgical treatment is feasible. It is recommended that the left side of the rib ectopia, such as non-normal physiological conditions, please consult a doctor in time to clarify the cause of the disease, if you need treatment, should be standardized under the guidance of the doctor.