Former Minister Binyamin Ben-Eliezer was evacuated on Saturday night to the Assaf Harofeh Hospital in after feeling unwell.
His condition is stable and he is fully conscious.
After a series of tests it was decided to keep Ben-Eliezer in the hospital overnight for observation and treatment.
Ben-Eliezer is currently on trial on charges of corruption. He is suspected of receiving money related to his public activities from various businessmen, and then using that money to purchase real estate, among other things.
The former Labor party leader is also suspected of exchanging foreign currency worth hundreds of thousands of dollars without reporting it to the authorities while attempting to hide the process.
As well, Ben-Eliezer is suspected of providing the Knesset Speaker with false financial statements, not reporting accumulated assets, and of not reporting income to tax authorities.
Ben-Eliezer resigned from the Knesset and retired from public life as the corruption investigation continued.
He had previously ran for the position of President, but dropped out of the race several days before the vote due to the investigation.
He has been suffering from health issues for several years, and was hospitalized for several days in December of 2014 due to fever.
Earlier that year, Ben-Eliezer underwent a kidney transplant but resumed political activity immediately after the surgery, which he described as "routine and easy."