INDEPENDENT MP Rob Oakeshott did not know what was wrong with him as his hands shook and eyes bulged while making the biggest decision of his political career.
Later, he discovered he had an incurable autoimmune disease at the time he chose to back Julia Gillard to be Australia's prime minister.
Now halfway into his term as crossbench kingmaker, Mr Oakeshott has this week spoken publicly for the first time about being diagnosed with Graves' disease.
Mr Oakeshott said he carried the the most severe and undiagnosed symptoms around with him during and after the 2010 election.
Even during his much-criticised 17-minute speech his body was failing, contributing to a loss of sleep throughout the tumultuous period of days that ended in a delicately poised Parliament. The condition caused his eyes to bulge, heart to race and led to an uncontrollable shaking in his hands visible to family, friends and the TV-watching public.
''Because of the shaking hands, family members were asking if I was getting Parkinson's disease,'' the 42-year-old Lyne MP said.
''People who saw me on TV sent me letters about it.''
A doctor diagnosed him with the condition after the new government had been formed.
He said he had stopped taking medication because the disease was now under control.
Looking back on his decision to support Ms Gillard, he has no regrets despite the pressure he was under and the baffling health concerns he had to overcome. ''Frankly, I was faced with a bugger of a choice,'' he told the Sunday Canberra Times.
Mr Oakeshott said his difficult decision to support Labor over the Coalition in 2010 reflected the same challenges the voters faced.
''Both leaders are more disliked than any political leaders in the past 20 years,'' he said.
''I get constantly tested about why I backed Gillard. Whenever I'm asked [in the electorate], I respond by saying 'so you want me to go with Tony Abbott?'.
''And they say 'no, no, no'.''
He said both major parties lacked a base of supporters and were culturally hollow.
Labor had so far met all the terms of its deal with him which have included action on climate change and delivering hundreds of millions of dollars into his Lyne electorate. An unabashed supporter of Malcolm Turnbull, he said his support for the former Liberal leader was because of policy and not necessarily due to personality.
He admits any possibility of Mr Turnbull rolling Mr Abbott for the Coalition leadership could be a game changer but would not see Mr Oakeshott automatically switch allegiance.
''Malcolm symbolises the Liberal that believes in micro-economic reform - with a conscience.''
Looming challenges for the self-described socially progressive Mr Oakeshott include the gay marriage vote. His electorate has made it clear to him it thinks marriage is between a man and a woman. He will therefore vote against reforms in favour of gay marriage in line with his electorate's strong feelings, unless he said lobbyists could somehow change his community's sentiment. His view of the gay marriage debate is that it is a waste of time for politicians.
''This would not be an issue if in 2006 John Howard had not opened up the Marriage Act and inserted the term 'man and woman'.
''The High Court would have been the appropriate place for this to be resolved [before Howard's changes to the act].''
According to his numbers, the House of Representatives will not support moves to introduce gay marriage.
No matter the Parliament's decision, he expected it would be challenged legally and predicted the High Court would make the final decision anyway.