Former Big Brother winner Reggie Bird has been diagnosed with a mysterious condition after months of medical tests.

Bird, who won the 2003 series and who now goes by the name Reggie Sorensen, was told by doctors that she had Pyrrole disorder six weeks ago.

It is a a biochemical imbalance that can cause depression, mood swings, deficiencies in zinc and vitamin B and sensitivity to light and sound.

Former Big Brother winner Reggie Bird. Image via Facebook.

The 41-year-old recently told Woman's Day that it was a relief to finally discover what was causing her symptoms after exhaustive, ongoing tests.

"I decided to try a different approach and see a naturopath, who took one look at me and heard my symptoms and said, 'I think I know what's wrong with you'," she said. "I can't tell you how good it was to find out what it was."

WATCH Reggie Bird discuss life after Big Brother below. Post continues after video...

Bird is mum to an eight-year-old daughter, Mia, and a six-year-old son, Lucas.

It's just the latest health battle for the single mother - who lives with a degenerative eye disease that's left her with ten per cent vision, and her young son has cystic fibrosis.

Reggie herself was initially tested for cystic fibrosis in an effort to discover the cause of her symptoms, but was given the all-clear.

Reggie and son Lucas. Image via Facebook.

We wish Reggie and her family all the best in this latest health issue.

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Winner of BBAU 14 Ryan

Ryan

Travis

Skye. Screenshot via Big Brother

Priya

Intruder Penny

Intruder Lina. Screenshot via Big Brother

David

Leo. Screenshot via Big Brother

Intruder Richard

Cat

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Lawson. Screenshot via Big Brother

Intruder Marina

Jason

Lisa

Sandra

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Tom