The statement continued, "He is grateful for the concerns and well wishes of Georgians, colleagues, family and friends."
In addition to noting that Lewis remained in the hospital until the doctor's observations are completed, the statement said, "Please stand by for official news regarding his condition."
No other details were provided about his condition.
Lewis has represented Georgia’s 5th Congressional District since 1987.
RELATED: Five things to know about John Lewis
He was among key activists in the civil rights movement, taking part in the Nashville lunch counter sit-ins, the 1961 Freedom Rides, the 1963 March on Washington and the Bloody Sunday march in 1965, where he was beaten in the skull by a state trooper in Selma, Alabama.
The septuagenarian hasn't been slowing down lately. Just last month he joined thousands of people marching in Atlanta as part of the nationwide March For Our Lives against gun violence.