Attention deficit hyperactivity disorder (ADHD) is a developmental condition marked by persistently high levels of inattention, hyperactivity, and impulsive behavior. ADHD is often diagnosed in childhood, but it can affect adults as well. In fact, almost 7% of children and 4% of adults have been diagnosed with ADHD at some point in their lives.

ADHD is believed to be caused by a variety of genetic and environmental factors. The exact cause has yet to be determined. However, we know that ADHD has a strong genetic component: researchers estimate that one-third of children with ADHD have at least one relative who also has it.
The main symptoms associated with ADHD are inattentiveness, hyperactivity, and impulsivity. Symptoms can vary depending on the type of ADHD you have—primarily inattentive type, primarily hyperactive-impulsive type, or combined type—and they can change over time as you age. To be diagnosed with ADHD, you must display symptoms for at least six months in at least two different settings.
ADHD can be diagnosed by psychological evaluation (typically by a psychologist or psychiatrist). Symptoms typically appear early in life, often between the ages of 3 and 6, and due to the nature of the symptoms, it can cause problems at school, work, home, and in relationships.

Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder characterized by inattentiveness, hyperactivity, and impulsivity. ADHD symptoms start before age 12, and in some cases may continue into adulthood. ADHD is one of the most common mental disorders among children.
It is normal for all children to be inattentive, hyperactive, or impulsive sometimes—especially young ones. For children with ADHD, these behaviors are more severe and occur more often. Symptoms affect a child’s behavior at home and school and can cause difficulty with making and keeping friends.
Attention deficit hyperactivity disorder (ADHD) is a condition that affects an estimated 5% of children, and about half of them will carry those symptoms into adulthood. ADHD can make it hard for people to control their behavior, stay on task, and pay attention. It can also affect people’s ability to get things done.
People with ADHD tend to experience more problems at work, school, home, and in relationships than others do—but the good news is that there are ways to manage ADHD symptoms and make life easier.

The disorder is a neurodevelopmental psychiatric disorder with the required symptoms being inattention and/or hyperactivity-impulsivity that is present for more than 6 months to an extent that is disruptive and inappropriate for a person’s developmental level.
The symptoms of ADHD vary by person. If you or your child have been diagnosed with ADHD, you will have a combination of symptoms in at least two different settings — for instance at home and at school. And these symptoms will be severe enough to cause problems in your everyday life.
Inattention, hyperactivity, and impulsivity are normal behaviors often found in children. However, when these behaviors continue in a child over a period of time, it may be a sign of Attention Deficit Hyperactivity Disorder (ADHD).
The signs and symptoms of ADHD vary with the age of the child. For instance, preschoolers with ADHD tend to have more symptoms of hyperactivity and impulsivity; whereas older children are more likely to have symptoms of inattention.