Ashley Monroe has been diagnosed with a rare type of blood cancer, the singer shared via Instagram on Tuesday (July 13). Her post reveals her positive mindset about her prognosis, and that she'll begin chemotherapy on Wednesday (July 14).

It's been "a few months," Monroe explains, since her doctor did some routine lab work and discovered that the singer was anemic. "I was like, FINE, I’ll just double up on cheeseburger patties, take some extra vitamins and call it a day," she says — but when her red blood cell count continued to fall and other numbers looked "fine," a bone marrow biopsy led to her diagnosis with Waldenstrom macroglobulinemia (WM), also known as lymphoplasmacytic lymphoma.

WM, per the American Cancer Society, is a type of non-Hodgkin lymphoma (NHL). Between 1,000 and 1,500 people are diagnosed with it per year, or about three per million people per year. The chance of diagnosis with WM increases with age — the average age of diagnosis is 70, though Monroe is only 34 years old — and it's more common in men than women.

Monroe says the disease has made her "pretty severely anemic, and I feel it." As she prepares to start chemotherapy, she's trying to keep a positive outlook: "I’m thankful I have an illness that is VERY live with-able. I’m thankful there IS a treatment that actually works to fight what is causing harm to my body," Monroe writes, adding that she's "THANKFUL for friends and family who have gathered around me praying and sending flowers and letting me lean on them during this super weird chapter of my life. Thankful for my angel son. Who I am fighting for the most."

In her post, Monroe expresses gratitude for her doctors at Vanderbilt University Medical Center in Nashville, who have helped her "[do] my research and ... [weigh] every option." She asks fans to refrain from offering medical advice, but to send prayers.

"I DO believe in the power of prayer guys. I also believe in the power of love healing us all on an even deeper level," Monroe says. "I love you all big. Here I go 💪🏼🙏❤️"

Monroe, both a solo artist and a member of the Pistol Annies, is the mother of one son, Dalton William Danks, who will soon be four. She is married to John Danks, a former professional baseball player, who the singer says has "be[en] my rock and the best dad to Dalton" as she copes with her diagnosis.

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