First lady Melania Trump received a visit from her husband after she underwent a “successful” procedure to treat a benign kidney condition.
She was expected to remain in hospital for the rest of the week, her staff said.
President Donald Trump took a helicopter to Walter Reed National Military Medical Centre to visit her and tweeted that his wife was in “good spirits”.
Mrs Trump, 48, had the embolisation procedure on Monday morning.
Heading over to Walter Reed Medical Center to see our great First Lady, Melania. Successful procedure, she is in good spirits. Thank you to all of the well-wishers!— Donald J. Trump (@realDonaldTrump) May 14, 2018
The president spoke with Mrs Trump before the procedure and with her doctor afterwards, the first lady’s office said.
The president tweeted shortly before arriving at Walter Reed outside Washington, saying it was a “successful procedure”, describing his wife as being “in good spirits” and offering his thanks “to all of the well-wishers!”
The White House did not offer any additional details on Mrs Trump’s condition.
She was last seen in public on Wednesday at a White House event where she joined the president to honor military mothers and spouses for Mother’s Day.
Two urologists who have no personal knowledge of Mrs Trump’s condition said the most likely explanation for the procedure is a kind of non-cancerous kidney tumour called an angiomyolipoma.
They are not common but tend to occur in middle-aged women, and if they become large enough, they can cause problematic bleeding, said Dr Keith Kowalczyk of MedStar Georgetown University Hospital.
“The treatment of choice” is to cut off the blood supply so the growth shrinks, added Dr Lambros Stamatakis of MedStar Washington Hospital Centre.
Doctors do that with an embolisation, meaning a catheter is snaked into the blood vessels of the kidney to find the right one and block it.
Most of the time, these benign tumours are found when people undergo medical scans for another reason, but sometimes people have pain or other symptoms, Dr Kowalczyk said.
Many times, embolisation patients go home the same day or the next.
The president had no public appearances scheduled for Monday and declined to answer shouted questions from reporters about how his wife was feeling as he departed the White House for Walter Reed.
.@SecondLady & I are relieved that our dear friend @FLOTUSâ medical procedure was successful & are praying for her swift recovery. Grateful to the great medical team at @WRBethesda, & look forward to her full recovery & return to work on behalf of Americaâs children #GetWellSoon!— Vice President Mike Pence (@VP) May 14, 2018
The former model from Slovenia is Mr Trump’s third wife, and the couple have been married for 13 years.
They have a 12-year-old son named Barron.
Mrs Trump, who has been gradually raising her profile as first lady, recently hosted her first state dinner and launched a public awareness campaign to help children.
With the president watching, Mrs Trump last week unveiled the “Be Best” campaign, which she said will focus on childhood well-being, social media use and opioid abuse.
Mrs Trump joined her husband last month to host the prime minister of Japan, Shinzo Abe, for a two-day summit at the Trumps’ Florida estate, and the Trumps hosted Emmanuel Macron, the president of France, at the White House on a three-day state visit, including a lavish state dinner.
Mrs Trump also represented the administration at the April funeral of former first lady Barbara Bush.
The Trumps and their marriage have been under scrutiny in recent months after revelations that a porn actress was paid 130,000 US dollars in hush money to keep quiet about claims she had sex with Mr Trump in 2006.
Mr Trump has acknowledged reimbursing his lawyer for the payment to porn star Stormy Daniels but denies her allegations.
Separately, a former Playboy model has revived her allegations of a 10-month affair with Trump in 2006.
Mr Trump also denies the allegations from Karen McDougal.
Mrs Trump has, at times, has been noticeably absent from her husband’s side.
But both made a point of displaying affection during last week’s Rose Garden event where the first lady announced her “Be Best” initiative.
The first lady lived full time in New York during the administration’s opening months so Barron would not have to change schools midyear.
She and Barron moved into the White House last June.