AP
"Early this morning, Senator Reid was not feeling well and as a precaution decided to go to the hospital. Tests have been conducted and everything is normal. He is alert, resting and feeling better," Reid's office said in a statement.
"Doctors have asked that he remain in the hospital for observation so he will not be working today."
Friday is the last day of work in the Senate this year, as senators wrap up what has been a busy schedule before holiday recess. Late Thursday night, the Senate passed the National Defense Authorization Act. The Senate is holding six votes on judicial and executive nominees Friday morning.