Three subtle symptoms of kidney cancer as 3 Doors Down's Brad Arnold announces stage four diagnosis

There are three subtle signs of kidney cancer to be aware of after 3 Doors Down's Brad Arnold shared his devastating diagnosis.

The 46-year-old took to social media on Wednesday (May 7) to reveal he has stage four clear cell renal carcinoma, which has spread to his lungs.

The Kryptonite hitmaker told fans in an Instagram video: "I'd been sick a couple of weeks ago and went to the hospital and got checked out.

"I actually got the diagnosis that I have a clear cell renal carcinoma that has metastasized into my lung... and that’s stage four, and that's not real good.”

He went on to confirm that the 3 Doors Down's upcoming shows this summer had been canceled. "And we're sorry for that," he added.

The band was scheduled to play Welcome to Rockville Festival in Daytona Beach, Florida next week ahead of a 21-date US tour.

Arnold concluded the video: “I'd love for you to lift me up in your prayers every chance you get," adding: "I think it’s time for me to go listen to ‘It’s Not My Time’ a little bit, right?" - referencing the band's 2008 hit about resilience and refusing to give up in the face of adversity.

What are the symptoms of kidney cancer?

Some 62,000 Americans are diagnosed with kidney cancer each year, as per the Cleveland Clinic. It's most common in people between the ages of 65 and 74.

Several factors can increase the risk of kidney cancer, including older age, smoking, obesity and high blood pressure.

Mayo Clinic writes that kidney cancer doesn't usually cause any symptoms at first.

However, over time, some may develop - including three that are rather subtle.

These include a loss of appetite, tiredness and unexplained weight loss.

More obvious sings might manifest as a pain in the side or back, which doesn't go away and blood in the urine, which can turn pee pink, red or cola colored.

Contact your doctor should you have any symptoms or concerns.

Fans were quick to flood the comments with messages of love and support.

3 Doors Down rose to fame with their 2000 debut album The Better Life, which went seven-times platinum and launched them into mainstream success.

They've released five more albums since, with Arnold remaining the band’s only original and longest-serving member.

The band made headlines in 2017 for performing at Donald Trump’s presidential inauguration, delivering several of their biggest hits.