Chicago Teachers Union president and potential mayoral candidate Karen Lewis remained hospitalized Tuesday after she was admitted to a hospital Sunday night.
According to a news release from the CTU Monday, Lewis was admitted after "experiencing discomfort," and was being evaluated.
Lewis' exploratory campaign aide Brandon Johnson told NBC 5 that Lewis was "feeling lightheaded" after a busy Sunday, so she took herself to a hospital.
Johnson noted that Lewis has "lost a considerable amount of weight -- more than 100 pounds," and she "wants to make sure there are no complications."
"Karen is a freedom fighter, a nationally recognized education advocate and the people's champ. She'll be back on her feet in no time. She is resting well and in good spirits -- and still thinking of creative ways to secure the future and city our students and their families deserve," CTU spokeswoman Stephanie Gadlin said.
Johnson said Lewis' illness "is not a stroke" and "she is ready to get back at it."
Lewis is considering challenging Mayor Rahm Emanuel in next year's election, but has not made a formal decision.
The Fioretti for Mayor campaign released a statement wishing Lewis a "speedy recovery."
"Karen is a valuable voice in the debate about our city’s future and we look forward to hearing from her soon," Fioretti campaign spokesperson Michael Kolenc said.