She took to social media to share the heartbreaking news with her fans: "In the words of the legendary Frank S - I'm afraid the time has come my friends. It's very surreal. Thank you so much for all the support I've received".
The star had originally been diagnosed with breast cancer in November 2016, and has been documenting her journey ever since on her popular blog "Big C little me", as well as starring as a co-host on the podcast "You, Me and the Big C".
Tuesday, in a piece Rachael wrote before discovering her time was so cruelly limited, she shared her plans to prepare husband Steve and their three-year-old son Freddie, for the day when she would no longer be here.
Husband Steve said in a statement: "Rachael's death has left a huge hole in our flawless little family that we'll never be able to fill. You'll never know how much they meant to her".
He described her as "perfect in every way", adding "we will miss her more than words can say".
The Welsh journalist died at the age of 40 this morning, her husband Steve Bland announced today. "We are all so proud at what she achieved - a truly heroic broadcaster and lovely wife, daughter and mum". It's our job to do that now with Steve and Freddie'. But within two months, scans showed her cancer had spread. "But some of the POVs scared me; some were downright insensitive".
But in the end, it worked out ok and our 4 little embryos - the remainder of our potential Bland 5-a-side squad - were sent off to chill out in the freezer for the foreseeable'. I love a game of "guess the results from the medic's demeanour"... my breast-care nurse hugged me on the way in and the surgeon had on her "bad news head-tilt".
Fellow podcast presenter Lauren Mahon said: "Heartbroken doesn't cut it. Steve, Freddie and family I love you".
The podcast reached number one on the iTunes chart in early September - an ambition of Bland's, which her husband tweeted had made her "very happy". So moved by her strength and bravery, her honesty, as a mum, as a woman.
Bland's death comes just two days after she announced over Twitter she had been given only "days" left to live by her doctors.
Livesey said: 'She would be on air and there would be breaking news and she was as consummate a BBC professional as you could find.
"I hope he will come back to it through his life and it will resonate in different ways at different stages".