Hello - Not medical professionals, physicians, and so forth, here at our site, it's best to contact your physician to discern medical jargon. I have been a medical transcriber/medical language specialist for years, and know these are abbreviations. HX means history. DX means diagnosis. So HX AS would allude to having a history of ankylosing spondylitis. And, then DX AS would mean one has a diagnosis of ankylosing spondylitis.
Should you be trying to decipher a medical report to understand your disease process, it's best to have a heart-to-heart conversation with the ordering/treating physician. Physicians have answers, treatments, and plans to keep you on the right track. Wishing you the best. Rebecca (team member)