Inattention. People who are inattentive have a hard time keeping their mind focused on one thing and may get bored with a task after only a few minutes. Focusing conscious, deliberate attention to organizing and completing routine tasks may be difficult. You may notice restlessness, procrastination, problems remembering obligations, trouble staying seated during meetings or activities, or starting multiple projects at the same time but rarely finishing them.
Hyperactivity. People who are hyperactive always seem to be in motion. They can't sit still and may dash around or talk incessantly. Children with ADHD are unable to sit still and pay attention in class. They may roam around the room, squirm in their seats, wiggle their feet, touch everything or noisily tap a pencil. Older adolescents and adults with ADHD may feel intensely restless.
Impulsivity. People who are overly impulsive seem unable to think before they act. As a result, they may blurt out answers to questions or inappropriate comments, or run into the street without looking. Their impulsivity may make it difficult for them to wait for things they want or to take their turn in games. They may grab a toy from another child or hit when they are upset. They often have difficulty making and keeping friends.
SOURCES: Heart Rhythm Society. American Academy of Pediatrics. The Food and Drug Administration. The National Institute of Mental Health. Attention Deficit Disorder Association. The American Academy of Family Physicians.