Normally, at what age will you start to notice the signs of an ADHD child?

Kids as young as 2 or 3 years old can display symptoms of ADHD. Some of these symptoms include inattention, hyperactivity, and impulsivity are symptoms of the condition at any age. However these behaviours occur in children without ADHD as well. Unless the symptoms continue for over 6 months, then the child will not be diagnosed with adhd. http://www.healthline.com/health/adhd/toddlers#RecognizingADHD1