Spokeswoman Lea Anne McBride said that doctors found his EKG unchanged.
The doctors, according to a statement released by the vice president's office, say he was suffering from a reaction to some medicine he was taking for a foot ailment, retaining fluid because of that medicine, CBS News senior White House correspondent Bill Plante reports.
He's been placed on a diuretic, a medicine to get fluid out of your body.
Cheney went to the hospital at 3:00 a.m., his office said.
Whenever the vice president goes to the hospital, alarm bells go off because he's had four heart attacks and wears a pacemaker and has had other problems that have sent him to the hospital, reports Plante.
The foot ailment forced Cheney to use a cane on Friday.
McBride said the foot condition was not related to surgery last September to repair aneurysms behind both knees or the 64-year-old vice president's lengthy history of heart problems. He has had four heart attacks, quadruple bypass surgery, two artery-clearing angioplasties and an operation to implant a special pacemaker in his chest.