Running and yelling all over the house. Constant interruptions. Taking part in risky or dangerous behaviors without thinking of the consequences. Why is one child so much more active and impulsive than other children? Look at the typical behaviors of a child with ADHD.
Young children are typically highly active and don’t always think of the risks they take as they play and roughhouse. However, children with ADHD seem to take these behaviors to a higher level, running all over the house and yard, seemingly unable to tire themselves out. They also place themselves in dangerous situations more frequently (climbing trees or roofs), interrupt you or others, bug siblings and friends and become easily distracted when they should be working on a task or homework.
These are some of the typical behaviors of a child with ADHD –– but, because most healthy children are usually active, it isn’t always easy to say, “I think my child may have ADHD." If you do have a child diagnosed with ADHD, learn more about some of the behaviors you may witness and have to help control.
Children with ADHD are generally highly physically active. They seem to need to be in motion from the moment they get up - running when they could walk, climbing furniture, scaling fences and jumping down on the other side, fidgeting at the dinner table or at their desk in school, jumping up from their desk frequently and unable to “slow their motor" until they go to bed. 
While all children are active, hyperactivity in a child with ADHD has to be present for six months or longer for diagnosis. This hyperactivity must also transfer from one setting to another (home to school to church) and it has to prevent the child from functioning at school, at home and with friends. 
Children with ADHD may be more impulsive than children who do not have ADHD. This means they act on a thought or idea without thinking of the possible consequences, which causes problems at home, school, in the playground and with friends and siblings.
This behavior may manifest itself in some outright dangerous behaviors, like running into the street without checking for traffic, climbing buildings to get to the roof or climbing a high tree. Children with ADHD may suffer injuries more frequently than children without ADHD, winding up in the emergency room for treatment of an injury sustained during an impulsive escapade. 
The child with ADHD who is impulsive or hyperactive experiences racing thoughts and has to express them quickly so they aren’t lost. Unfortunately for the parents, friends, siblings and teachers of this child, this leads to frequent interruptions.
Children with ADHD aren’t able to “read" social cues, so they don’t understand, first that they have interrupted someone who may be talking or be busy with a mental task. Second, these children misunderstand facial expressions, so when they interrupt someone, they are genuinely confused when that person gets frustrated or angry. 
The child with ADHD experiences more frustration than other children. Because they don’t understand social cues and they “tune out" from instruction they find themselves missing essential information. As they go through their day, their frustration builds until it erupts in a sudden, loud tantrum.
A typical tantrum may look like a “melt-down," with the child crying, screaming, hitting their head against the floor or a wall or kicking an object or another human being. 
Another one of the typical behaviors of a child with ADHD is bugging other people. Again, because ADHD children are unable to read and interpret social cues, they do not understand that poking siblings, classmates, parents or friends bothers them. When they get angry and retaliate, an ADHD child is genuinely confused, not understanding that physical boundaries were crossed.
When this behavior takes place in the classroom, the child develops the undeserved reputation of being the “classroom pest." The teacher may buy into this, not knowing why a student seems to “want" to bug others.