order here : https://rehabilative.com/what-is-adhd-and-why-does-it-happen/ The complete form of ADHD is "attention deficit hyperactivity disorder." most people related ADHD to autism, but it's different altogether. Though both medical ailments have some common symptoms. There are three primary forms of ADHD: - ADHD, combined type ADHD, impulsive/ hyperactive type ADHD, inattentive and distractible type Having ADHD can make your life miserable and can get worse with time. In most cases, aging can also lead to cognitive changes. Research is being done to know the exact cause of developing ADHD symptoms. But still far, no proper conclusion is made for this. However, the doctors claim that it's all related to the abnormal genetics of the person. Plus, environmental factors also play a significant role in developing ADHD.