Attention-Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental condition that affects attention, executive functioning, impulse control, and organization. While many people associate ADHD with hyperactivity, symptoms can look very different from person to person and often change with age. Children and adults with ADHD may experience challenges at school, work, or home, but an accurate evaluation can help clarify whether ADHD—or another condition—is contributing to those difficulties. Understanding the cause is the first step toward effective support, treatment, and long-term success.