The tenor, who has performed for both the Queen and Emperor Hirohito of Japan at the Imperial Palace, even revealed he was close to death before receiving surgery.
While both incidents happened over a decade ago, Russell can still recall the details of the traumatic experiences. Take a look at what he's said about what paramedics were saying to him and why he delayed surgery...
When did Russell Watson suffer his first brain tumour?
Russell was first diagnosed with a brain tumour in 2006, when he was 39 years old, after suffering from headaches and loss of peripheral vision – both of which doctors initially presumed were caused by stress from his successful career.
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"Suddenly I felt as if I was going to die. My head was throbbing and my vision had deteriorated so badly it felt as if I was seeing through a small tube," Russell told the Evening Standard, as he recalled his plane trip to Los Angeles to record an album.
"Thinking I might be dehydrated, I kept on drinking water and taking tablets, but nothing made any difference. It felt as if someone was pressing a knife into the bridge of my nose."
After being diagnosed with a tumour, he was taken to St George's Hospital in Tooting to have it removed through his nose.
When did Russell Watson suffer his second brain tumour?
Unfortunately, this wasn't the end of his battle. In 2007, Russell was diagnosed with his second brain tumour which was even more dangerous than the first.
Russell recently opened up about his health to his fellow I'm A Celeb stars
The 54-year-old told his fellow I'm A Celebrity stars: "The first wasn’t life threatening, it was painful and I nearly lost my vision." However, his second one caused a haemorrhage which meant he struggled to wake up from his sleep.
"My assistant found me, called the paramedics and I knew I was in trouble because the paramedic kept saying ‘stay with us, stay with us’. We got to the hospital and they operated," he continued.
Why did Russell Watson delay surgery on his second brain tumour?
Shortly after it happened, Russell revealed he delayed his operation in order to see his two children, Rebecca and Hannah, over fears he may not survive the procedure.
The famous tenor revealed he delayed surgery to see his two daughters
"I was aware I was in a lot of trouble and I wanted to make sure I'd see them in case anything happened to me and that's why against the advice of my surgeon I held the operation up until the next morning," the Evening Standard reported in 2007.
What has Russell Watson said about his near-death experience?
Luckily, he recovered from surgery, but Russell told Vernon Kay he felt he had been close to death. "I was in the MRI scanner and I could see this long strip of light," he said.
"I was thinking, if I go to that door I’m out of here and the pain stops and I’m away, and all I could think about was my children and slowly slowly whilst thinking about my children the clatter clatter of the MRI came back and I thought, I’m going to beat this."
How is Russell Watson doing now?
Russell credits wife Louise Harris with transforming his life
Russell is now married to Louise Harris, the woman he credits with transforming his life, after meeting her in a restaurant in Alderley Edge.
Speaking of their Spanish ceremony, which took place in August 2015, he told HELLO!: "Louise has taught me many things but most of all how to love. I have never been more content. It really is a fairytale ending."