ADHD, or Attention-Deficit/Hyperactivity Disorder, is a common neurodevelopmental disorder that affects how a person focuses, controls impulses, and regulates activity levels. It typically presents in childhood and can continue into adulthood.

The core symptoms of ADHD fall into two categories:

1. Inattention: Difficulty sustaining attention, following through on tasks, organizing activities, and being easily distracted.
2. Hyperactivity-Impulsivity: Excessive fidgeting, restlessness, difficulty staying seated, talking excessively, interrupting others, and acting without considering consequences.

ADHD can affect various aspects of life, including academic performance, work, and relationships. Diagnosis is usually based on a comprehensive evaluation that includes medical history, behavioral assessments, and sometimes input from teachers or family members. Treatment often involves a mix of behavioral therapies, psychoeducation, and, in some cases, medication to help manage symptoms and improve functioning.