ADHD is a neurodevelopmental disorder characterized by inattention, hyperactivity, and impulsivity. It affects about 5% of children worldwide, with boys four times more likely to be diagnosed than girls. While the exact causes are unknown, ADHD is thought to involve genetic and environmental factors such as prenatal exposure to alcohol or tobacco. Symptoms of inattention, hyperactivity, and impulsivity can cause difficulties at school, home, and with relationships. Treatment involves medication, behavioral therapy, lifestyle changes, and accommodations to help those with ADHD succeed.