If the pain in the chest of a 10-year-old girl is not caused by localized swelling due to trauma, it is considered to be caused by breast development. You can take your child to the hospital for a breast ultrasound examination to determine whether the breast nucleus has grown, and if it has grown, it can be diagnosed as early sexual development. The normal age of a girl is 11 years old, but nowadays, many children are affected by diet and environmental factors, and they will develop earlier. 10-year-old girls with breast development belong to the advancement of sexual development, which has the following effects on the children: 1) the children will be shorter than the children in their future life height; 2) it may increase the psychological burden. Therefore, once it is clear that it is breast development, it is necessary to do bone age and uterus and ovary ultrasound examination, to clarify whether the child’s height is lost and the degree of sexual development, according to the actual situation of the child to give further treatment.