Ryan Sutter reveals details on illness he says he's battling

Ryan Sutter is opening up more about the unidentified illness he says he is fighting.

After his wife, Trista Sutter, who was in the first season of "The Bachelorette," posted details surrounding his health battle over the weekend, he shared more about his symptoms and current condition.

"In February I started my fire career over and began an 18 week fire academy with Denver Fire," Sutter wrote in a post on Tuesday. "Towards the end of that process I felt more and more worn out and began feeling occasional "flu like" symptoms."

He said he got tested for COVID-19 several times and did not receive any positive test results. He finished the academy training four months later and said he left hoping he "would begin to recover and feel better."

MORE: Former 'Bachelorette' Trista Sutter says husband 'struggling for months' with mystery illness

Describing his current condition, Ryan Sutter said that he feels "worse" than he did five months ago.

"Though I am functional and continue to work my regular fire schedule, I am experiencing a battery of symptoms which include: fatigue - sometimes almost paralyzing, deep body and muscle aches, fevers, night sweats, full body itching with no rash, headaches, neck and throat swelling, congestion, light headedness, nausea, and just general all around not feeling good," he posted.

The fireman also said that after having "several blood tests and a CT scan" that he has "a high ANA [antinuclear antibodies] Titer and low WBC [white blood cell count] but nothing else has proven anything conclusive."

According to the Mayo Clinic, doctors often order ANA tests "for a suspected autoimmune disease such as lupus, rheumatoid arthritis or scleroderma."

"In most cases, a positive ANA test indicates that your immune system has launched a misdirected attack on your own tissue -- in other words, an autoimmune reaction," the medical clinic states. "But some people have positive ANA tests even when they're healthy."

Sutter said he feels "about 70%" and is not currently taking medications. "I don't believe I have anything contagious as no one else in my family has been sick nor has anyone I have worked with or associated with been sick," he shared.

MORE: Trista and Ryan Sutter relive their season of 'The Bachelorette'

In a follow-up post, he said he's heard from others who have not been able to find answers concerning their medical issues.

"The struggle to find answers in the medical world and support through the insurance industry is frustrating and lacking," he wrote. "One must truly and persistently advocate for himself/herself if they hope to find answers or, at the very least, rule out possibilities."

He also shared a photo with his wife, who he described as "the best wife in the world," and said he has a great support system and feels "well prepared" to address his health battle.

Ryan and Trista met on season one of "The Bachelorette," which aired in 2003, and married that same year. They have two children: a son, Maxwell Alston, 13, and a daughter, Blakesley Grace, 11.

Ryan also thanked his followers for their well-wishes and encouraged people to support one another. "Please don't worry about me. I will be fine," he wrote. "If you must worry, worry about each other."

In an exclusive statement to "Good Morning America," Trista and Ryan Sutter addressed the support they've received and asked for privacy:

"Thank you to everyone for the overwhelming amount of support and sincere concern in regards to recent news concerning my personal health. It has become quite apparent many of you have either known someone or have personally experienced similar situations and for that we share our greatest condolences.

As you can imagine, during trying times of any kind, the comfort and support of family is most important and is something for which both Trista and I are indescribably grateful. We are working closely with our chosen network of top medical professionals and health advisors to search for the answers we need and are exploring a multitude of possibilities to get me back in good health. We will update you when we feel progress has been made and is appropriate to share. Moving forward, we hope that you will respect our privacy and that of my place of employment and give us the space and time required to dedicate our attention to the unknown battle ahead."