Pervasiveness of attention difficulties and hyperactivity For a diagnosis or description of ADHD a child would be expected to show the above difficulties in more than one setting, e.g. at school and at home. It may also be because the problems are mild, or because the family has handled the attention lack at home in such a way that it is not evident there is a major problem, or because the child is very young. In those cases it is quite reasonable for parents not to consider that their child has an attention deficit problem. Boys are more likely to be affected. Grand mal or petit mal epileptic seizures can cause a child to become drowsy, impairing their attention.
Epilepsy can also cause unusual behaviour and lead to abnormal perceptions.
Hearing problems such as deafness or glue ear can make it hard for a child to follow instructions and make them appear inattentive. Reading problems, making it hard to complete tasks or follow instructions. Obsessive-compulsive disorder leads to people following strange rituals that preoccupy their thoughts and distract their attention. Gilles de la Tourette's Syndrome involves repetitive involuntary jerking movements of the body and sudden outbursts of noise or swearing. Autism and Asperger's Syndrome as this leads to difficulties in understanding and using language.