Attention deficit hyperactivity disorder is a difference in brain development that can affect ability to focus and self-control.

Research shows that kids who show symptoms of ADHD around age 3 may go on to meet the criteria for a diagnosis when they are 13.

Some researchers think that being male may put you at higher risk for ADHD.

ADHD is often thought of as a "boys' disorder." But it's important to note that ADHD can look different in girls.

The American Psychiatric Association (APA) has identified three types of ADHD. Each has different symptoms and treatments.

Your child can't sit still. They are talking a mile a minute. Are they just a high-energy kid? Or do they have ADHD?

If your child constantly has trouble focusing, there's a chance they might have the inattentive type of ADHD.

Two out of three kids with ADHD have one or more problems with learning, behavior, or mood. Doctors call this complex ADHD.

ADHD symptoms usually show up when children are young—around school age. But you might notice them much earlier.

Before you jump to any conclusions, consider what else could be causing these behaviors that look like ADHD.

Dyscalculia is a math learning disability or mathematics learning disorder. It can be associated with ADHD.

If you or your child has ADHD and less-than-perfect penmanship, you may have wondered if there's a connection. 

Some studies have found that different parts of the brain may be smaller in those with ADHD.

If your child has ADHD, they may have low levels of a brain chemical called dopamine.

Sometimes, going through a traumatic event can cause attention problems. But trauma and ADHD can be confused in diagnosis.

If you suspect that your child might have ADHD, start with a visit to their pediatrician.

When you find out your child has ADHD, you can turn to a team of pros who can get them the right treatment.

There's no single test to diagnose ADHD. The doctor will talk with the parents about ADHD symptoms they have seen.

If you suspect you or your child might have ADHD, your doctor has many ways to make a diagnosis. One is an ADHD rating scale.