US Supreme Court judge Ruth Bader Ginsburg has fractured three ribs after a fall on Wednesday, the court says.
The fall happened in her office at the Supreme Court in Washington.
Ms Ginsburg, 85, went home but was in discomfort and went to George Washington University hospital on Thursday morning, a statement said.
Tests showed that she had fractured three ribs on her left side and she has been admitted for observation and treatment.
It means Ms Ginsburg will not be present for Thursday’s investiture of new Supreme Court judge Brett Kavanaugh, whose appointment led to protests following allegations of sexual misconduct.
President Donald Trump, who nominated Mr Kavanaugh and described the claims against him as a “hoax”, is due to attend his investiture.
Ms Ginsburg has sat on the Supreme Court since 1993 after being appointed by President Bill Clinton and is seen as the most senior justice on the court’s liberal wing.
Prior to her appointment, Ms Ginsburg focused her work on women’s rights and started the first law journal dedicated to the topic.
Some of her legal opinions, coupled with her refusal to step down during the Obama era, have seen her gain popularity in some quarters and earned her the nickname Notorious RBG.