ADHD Say: ay-dee-aych-dee ADHD is short for attention deficit hyperactivity disorder. Kids who have ADHD find it difficult to pay attention and are hyperactive, which means they might have trouble sitting still. About 9% of kids have ADHD, which means about 9 in 100 kids has it. Back to Articles Related Articles Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.