Venus Williams accuses doctors of dismissing her fibroid symptoms for years and says it left her 'outraged'

Tennis icon Venus Williams has opened up on her terrifying battle with fibroids - and claimed that doctors initially misdiagnosed the problem as period symptoms.

Williams, who has won seven women's grand slam titles, discussed her painful experience during an interview with NBC News after alleging that she was unaware of the full extent of the problem despite seeking medical help.

After her menstrual cramps intensified, leaving her with heightened nausea, the 45-year-old says doctors dismissed her grueling period symptoms as 'normal' while failing to spot signs of fibroids - noncancerous growths that develop in the muscular wall of the uterus.

'It just got too bad, and I couldn’t handle it,' she admitted in the interview with NBC News' Zinhle Essamuah, which aired on Thursday.

'As bad as things were for me, crazy amounts of bleeding like you couldn’t imagine… my doctors told me it was normal,' Williams later added. 'I never realized (anything) was wrong.'

The American star reportedly knew she had fibroids, though doctors never identified how large they were. Medical professionals also failed to explain how they were related to the intense levels of pain, nausea and persistent anemia she was feeling from heavy periods, which led to repeated iron transfusions.

As a result, she suffered behind the scenes for years while juggling the issue with her career as an elite tennis player. 

'I’m sharing now because I was outraged that I didn’t know this was possible. I didn’t know what was wrong with me,' she insisted. 'No one should have to go through this.'

Williams, who recently turned down the chance to make a tennis comeback after over a year out, says she experienced heavy bleeding as adolescent and throughout her career, which impacted her energy on the court.

She was often flagged as being anemic when undergoing anti-doping tests, leading her to believe she was suffering from Sjogren's syndrom - an autoimmune condition which causes muscle pain, fatigue and trouble swallowing.

'I thought maybe it was autoimmune anemia,' Venus said. 'It was what I was dealing with inside, which was fibroids and something else I had never heard of, which is adenomyosis.'

Fibroids are incredibly common in young females, affecting 70 percent of white women and 80 percent of black women before they turn 50.

Williams says she would often wear more layers because she bled so much, meaning people might not notice if it seeped through one set of clothes. And during training at Wimbledon in 2016 she became so sick she couldn't eat.

'We had a doubles final to play next, and I was just lying on the floor in the locker room, like, "It’s gonna pass. It’s gonna pass,"' she recalled. 'Thank God Serena got the doctor ... and I was able to get up and eat and start playing — bad luck for the opponents.'