Understanding ADHD -- the Basics
ADHD is a chronic condition marked by persistent inattention, hyperactivity, and sometimes impulsivity. ADHD begins in childhood and often lasts into adulthood. About 30% to 50% of children with ADHD continue to have symptoms as adults.
Symptoms of ADHD can differ from person to person, but there are three basic types of ADHD. Each one is identified by some combination of hyperactivity, impulsivity, and inattention. When activity levels are normal or low, the type is usually called primarily inattentive. The symptoms of hyperactivity and possibly impulsiveness appear to diminish with age but are seen in the primarily hyperactive/impulsive type. The third type has some symptoms from each of the other two and is called the combined type.