A statement from the court said the 76-year-old justice was taken to Washington Hospital Center at 7:45 p.m. EDT as a precaution.
During the day, Ginsburg had received an iron sucrose infusion to treat an iron deficiency that had been discovered in July, the statement said.
About an hour later, she "developed lightheadedness and fatigue," the statement said. She was found to have slightly low blood pressure, which the court said can occur after the type of treatment she had received.
Although an examination found her to be in stable health, she was given fluids and taken to the hospital as a precaution, the court said.
The July evaluation found "that she was in completely normal health with the exception of a low red blood cell count caused by deficiency of iron. Intravenous iron therapy was administered in a standard fashion," the court statement said.
Ginsburg underwent surgery for pancreatic cancer in February but returned to work quickly.
Two months after her surgery, Ginsburg told law students at a symposium at Ohio State University that serving on the Supreme Court was "the best and the hardest job I've ever had." She said at the time that she wanted to match the tenure of Justice Louis Brandeis, who served for more than two decades and retired at age 82.
After the retirement in January 2006 of Justice Sandra Day O'Connor, Ginsburg was the only woman on the nine-member court until Sonia Sotomayor joined the court last August.
Nominated by President Bill Clinton, Ginsburg took her seat on the Supreme Court on Aug. 10, 1993. She had been a judge on the U.S. Court of Appeals for the District of Columbia Circuit since 1980.