“In general, you want to embolize it because you don’t want it to continue to get bigger and erode into the larger vessels of the kidney where it can cause significant bleeding,” he said. He added that embolizing in this case was “most likely a preventive thing.”

The procedure came just a week after Mrs. Trump formally kicked off a public campaign to encourage children to put kindness first in their lives, particularly on social media. She has generally maintained a low profile during her 16 months as first lady, focusing primarily on raising her son, Barron.

Mrs. Trump makes a point of leading a healthy lifestyle. In New York, she has said she would walk with ankle weights and eat seven pieces of fruit every day. “I live a healthy life, I take care of my skin and my body,” she told GQ in 2016. “I’m against Botox, I’m against injections; I think it’s damaging your face, damaging your nerves. It’s all me. I will age gracefully, as my mom does.”

The health of first ladies has long been a factor in White House life. Three first ladies died while living in the White House — Letitia Tyler (wife of John Tyler), Caroline Harrison (wife of Benjamin Harrison) and Ellen Wilson (wife of Woodrow Wilson) — and Andrew Jackson’s wife, Rachel, died between his election and inauguration.

Others have suffered serious ailments that, for much of the country’s history, were shrouded from the public. In recent decades, first ladies have been more open, although not in every instance. Betty Ford set the tone for modern times by being open about having a mastectomy to fight breast cancer. Following her example, Nancy Reagan also disclosed her own mastectomy, although she limited the details released.

Barbara Bush disclosed her Graves’ disease, a thyroid condition, while living in the White House. Her daughter-in-law, Laura Bush, however did not reveal that she had a skin cancer tumor removed from her shin until weeks later, deeming it “no big deal at the time.”