Inattention: Attention deficit disorder, is a subtype of attention deficit hyperactivity disorder that often manifests as limited attention span, forgetfulness and distractibility. People with inattentive ADHD make careless mistakes because they have difficulty following detailed instructions, sustaining focus, and organizing tasks and activities. They are easily distracted by external stimuli, and often lose things. These are all symptoms of Inattentive-Type ADHD; they are not personal defects.

Hyperactivity: Hyperactivity is a psychological or physical state of abnormally high activity, a symptom of certain medical or psychiatric conditions, and a common psychological syndrome. Hyperactivity includes increased movement such as fidgeting or constant movement, talking too much, difficulty concentrating, and other manifestations. Hyperactive behaviour usually refers to constant activity, being easily distracted, impulsiveness, inability to concentrate, aggressiveness, and similar behaviours.

Impulsivity: Impulsivity, or impulsive behaviour, is broadly defined as actions without foresight that are poorly conceived, prematurely expressed, unnecessarily risky, and inappropriate to the situation. Impulsivity is associated with undesirable, rather than desirable, outcomes.