Hillary Clinton is '100pc healthy', says aide after brain damage claim
"Thirty days in the hospital?" Rove reportedly said. "And when she reappears, she's wearing glasses that are only for people who have traumatic brain injury?
"We need to know what's up with that."
Mrs Clinton (66), who is the presumptive Democratic front-runner for the 2016 presidential race, was admitted to hospital in New York for three days to treat a concussion and blood clot that she suffered in a fall.
Her hospital stay prevented Mrs Clinton from testifying at the time about the deadly attack on the US mission in Benghazi, Libya.
Mr Rove's comments could be seen as a bid to inject the question of Clinton's health – and whether she is physically and mentally prepared for another gruelling presidential run – into the conversation about 2016.
Mrs Clinton's team quickly rejected Rove's comments.
"Karl Rove has deceived the country for years, but there are no words for this level of lying," her spokesman Nick Merrill said.As to her health, he added: "She is 100pc. Period."
Several Republicans had assailed Mrs Clinton for possibly exaggerating the seriousness of her condition in order to avoid testifying before Congress about the deadly attack in Libya on September 11, 2012.
In January 2013, she testified for seven hours about the crisis. On Tuesday, Mr Rove insisted that he had never said Mrs Clinton might have brain damage, as 'Page Six' had suggested."I never used that phrase," Mr Rove told Fox News.
"She had a serious health episode," he said, adding that Mrs Clinton spent a month from early December 2012 fighting a virus and dehydration which caused her to cancel a Middle East trip, and then there were the effects from her fall.
Mrs Clinton's team was "not particularly forthcoming" with details and ought to release her full medical records, which would be requested by US media anyway should she announce a run, he said.
Health concerns were fair game for all presidential candidates, he added, and pointed to the scrutiny that John McCain endured in 2008.
"My point is that Hillary Clinton wants to run for president but she would not be human if this didn't enter in as a consideration," Mr Rove said.
And he added: "This will be an issue in the 2016 race, whether she likes it or not."
The Democratic National Committee brushed away the strategist's initial remarks, saying: "It appears that Karl Rove's medical diagnoses are about as solid as his election night prognostications."
Mr Rove had predicted that the Republican presidential nominee Mitt Romney would defeat the incumbent Barack Obama in 2012.
Meanwhile, Mrs Clinton is keeping up a breakneck pace of speeches and appearances across the country and she is preparing a book tour to push her new autobiography, which comes out next month.