AuDHD is a shorthand term for people who are both autistic and have ADHD/ADD.
The two conditions can overlap and interact in complex ways — for example, combining deep focus and hyperfixation with distractibility or impulsivity. Many AuDHD people describe feeling pulled between opposing traits: craving structure yet resisting routine, needing stimulation yet tiring easily — experiencing the world with both autistic depth and ADHD intensity.
AuDHD is not a diagnosis in itself and many AuDHD’ers will only have one diagnosis (autism or ADHD) or none at all. In the UK, you could not get a dual diagnosis of autism and ADHD before 2018 so most people won’t be diagnosed with both. Clinicians were often taught that autism and ADHD couldn’t co-occur, so if you were diagnosed with one, the other was ruled out.
In 2018, the NICE guidelines were updated to support dual-diagnosis and professional training was updated to reflect this and by 2020/21 it was supposed to be routine, common practice that both conditions can occur in one person and it is possible to get a dual-diagnosis.