Can a child who has been tested and diagnosed with adhd actually have sensory issues that aggravate their ability to focus and stay calm?

Very thoughtful: I'm not sure what you mean by sensory issues, but i think it must be true. It seems very thoughtful and considerate of you to be aware of this. The child is lucky to have you around.

Yes: Children can have sensory issues related to all sensory modalities which can affect their focus and well-being. Common ones are related to textures (food, clothing), touch (deep or light pressure) even sight and sounds. Occupational therapists are key in treating these sensory overloads to help children remain calm.

Yes: Sensory integration disorder is often a rule out category or comorbid condition that interferes with attention in children. Try reading 'too loud, too fast, too bright, too tight' as a good book about sensory issues.