Joan Kirchner said in a statement that Isakson complained of feeling ill and dehydration.
"Sen. Isakson woke up [Monday] feeling ill. He was admitted to Northside Hospital to receive fluids and undergo tests," said Kirchner.
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Kirchner said doctors believe Isakson is suffering from a bacterial infection.
"Sen. Isakson is responding very well to the treatment and is feeling much better," said Kirchner.
"He met this morning with his Senate chief of staff at the hospital and hopes to be back at work soon," Kirchner said.
According to his official Website, Isakson entered politics in 1974 and served 17 years in the Georgia Legislature. In 1999, Isakson was elected to the U.S. House of Representatives for the first of three terms. He joined the U.S. Senate in 2004 and will be up reelection in 2010.
One of his biggest political achievements include his work Isakson as an original author of the No Child Left Behind Act.