“…a condition exhibiting one or more of the following characteristics over a long period of time and to a marked degree that adversely affects a child’s educational performance:

 (A) An inability to learn that cannot be explained by intellectual, sensory, or health factors.

(B) An inability to build or maintain satisfactory interpersonal relationships with peers and teachers.

(C) Inappropriate types of behavior or feelings under normal circumstances.

(D) A general pervasive mood of unhappiness or depression.

(E) A tendency to develop physical symptoms or fears associated with personal or school problems.” 
Children with the most serious emotional disturbances may exhibit distorted thinking, excessive anxiety, bizarre motor acts, and abnormal mood swings.

Many children who do not have emotional disturbance may display some of these same behaviors at various times during their development. 
However, when children have an emotional disturbance, these behaviors continue over long periods of time. Their behavior signals that they are not coping with their environment or peers.

Reference: https://www.parentcenterhub.org/emotionaldisturbance/

This is a great resource for parents who may want to learn more about their child's emotional or behavioral disorders or feel that their child may be showing certain behaviors or characteristics.