Carlos Julio Aponte, MD, still remembers his ankylosing spondylitis (AS) patient No. 1. The man, a former traffic controller, was referred to Aponte more than 4 decades ago, racked by such agonizing back pain since age 20 that he couldn’t hold a job. No one could pinpoint the source of the man’s “mysterious” ailment. One doctor suspected that the patient’s symptoms were all in his head and prescribed medication for that.

Aponte, a rheumatologist in Cleveland, asked his new patient when his back pain was the worst. In the morning, he replied. In fact, it took the man almost 2 hours to get out of bed and on his feet.

“I said, ‘Oh my god, you have ankylosing spondylitis!’ ” Aponte recalls.

Doctors today understand much more about inflammatory diseases like AS than they did in the 1970s. But even then, Aponte knew that morning stiffness that lasts more than an hour could be a telltale sign of AS.

By Don Markham’s count, it took him about 7 years to confirm that AS was responsible for his serious eye inflammation called uveitis. But when the 47-year-old Dallas native looks back, he thinks the correct answer actually may be closer to 30 years.

Markham remembers his mother strapping soothing hot towels on his knees when he was 10. The flares of pain would come and go. But those childhood episodes were mostly dismissed as growing pains. And they didn’t deter Markham from growing up playing football and lifting weights.

But around the time Markham turned 40, his life took a scary turn when he got uveitis, a possible complication of AS that affects the eyes.

“I basically couldn’t see. I could make out shapes, but I was very light-sensitive,” he says. “The best way to describe it is it’s like almost being blind, but you’re not blind.”

The scare lasted about 6 weeks. Markham’s eye doctors couldn’t figure out the cause but guessed that it could be “some kind of autoimmune disease.” Without clear answers, Markham once again chose to “blow it off.”

Several years later, Markham thought he had twisted his left knee while kayaking. His doctor noticed that his “inflammation markers were off the charts.” But once again, the doctors remained baffled. One thought he might have cancer. Another suggested the reason for the pain and spreading inflammation might be neurological.

“I don’t know how many diagnoses they tried to come up with, and none of them was correct,” Markham says. He struggled with the effects from his multiplying medications, including hallucinations. At one point, “I was almost kind of suicidal.”

After consulting nearly three dozen doctors — but not until a fateful visit to a rheumatologist in Dallas — Markham finally learned he had AS.

After one look at Markham and his medical history, the rheumatologist said, “I already know what you have, but I need to do a test to confirm it.”

Right away, Markham quit some of his medications and was weaned off others while he started on therapies to help with his AS. His recovery was rapid. He was back to lifting light weights in a few weeks and competing professionally in about a year.

Today, Markham’s AS has progressed to the point that his spine is slightly fused. He regrets the time he wasted on incorrect diagnoses.

Charis Ann Hill, a 33-year-old from Sacramento, CA, who uses the pronoun “they,” was raised by their mother in North Carolina. Their father, who Hill says wasn’t involved in their life, had AS.

“I knew he had a disease that I couldn’t pronounce the name of,” Hill says. “But I knew that it wasn’t going to happen to me because it was a ‘man’s disease.’”

Some 80%-95% of people with AS carry a gene called human leukocyte antigen B27 (HLA-B27). Children can inherit this gene from their parents. But you can get AS without carrying the gene. And the majority of people who have HLA-B27 don’t get AS.

Hill, a model, was an athletic kid who ran and played soccer. When Hill hit their teens, the pain around their knees and other joints started. But Hill dismissed the symptoms as sports-related aches.

By the time Hill moved to California for college, their “body started deteriorating.”

One doctor brushed off Hill’s intense low back spasms as sports-related, again. At the time, Hill thought that made sense.

Hill consulted another doctor, who suggested they had anxiety and wrote a prescription. But Hill was unconvinced. They thought their symptoms were similar to ones their father had. So, they reached out to their estranged parent. In February 2013, their father emailed back and advised them to seek medical care specifically for AS.

Hill was officially diagnosed the next month.

“I think a lot of people have relief when they finally know what’s going on,” Hill says. But they had the opposite reaction.

Hill saw their father once a year while growing up, and the memories of how the disease took a toll on his body brought on fear.

“Immediately, I thought that’s what my life is going to be,” Hill says. “I’m going to become my dad.”

It took time for Hill to come to terms with their lifelong condition. The long and frustrating quest to find a diagnosis was mentally and emotionally exhausting.

“Depression and chronic disease are like cousins, they hang out a lot,” Hill says.

On the flip side, Hill is grateful that their belated diagnosis allowed them to live care-free. It allowed them to have the time to indulge in adventures like bungee jumping, to play college soccer, and even to study abroad.

“I went through 5 years of having what I was going through, and that’s how long it took for me to accept it,” Hill says. “So don’t let people pressure you into accepting something before you’re ready.”