The chronic pain Lady Gaga has suffered for years is the result of fibromyalgia.

The pop superstar confirmed the cause of her health battle in a Twitter post on Tuesday (12Sep17) as she promoted her new Netflix documentary Gaga: Five Foot Two, in which she is filmed receiving injections to treat the severe muscle pain.

"In our documentary the #chronicillness #chronicpain I deal w/ (with) is #Fibromyalgia," she told fans on social media. "I wish to help raise awareness & connect (with) people who have it."

It's the first time Gaga has publicly acknowledged the diagnosis, which can also cause fatigue and memory and mood issues, after previously only referring to her battle with "chronic pain".

Last year (16), Gaga shared a photo of her shoulder being treated by a doctor, just days before she was due to take to the stage at the American Music Awards (AMAs).

"Having a frustrating day with chronic pain," she captioned the image, "but I find myself feeling so blessed to have such strong intelligent female doctors."

She later thanked fans for their outpouring of support, and shared a few of her personal remedies for the ailment on Instagram, explaining she uses an infrared sauna while wearing a thermal silver blanket, followed by a very cold ice bath whenever her body goes into spasm.

Gaga's fibromyalgia admission emerges four years after the Poker Face hitmaker had to cancel dates on her 2013 world tour. At the time, she was diagnosed with the condition synovitis, an inflammation of the joints, and a labral tear, and subsequently revealed she had actually broken her hip and was facing a complete hip replacement if she didn't heed doctors' advice to axe her shows and undergo surgery.

The singer premiered Gaga: Five Foot Two at the Toronto International Film Festival on Friday (08Sep17), when she also performed, just days after having to cancel a concert in Montreal, Canada due to illness.