The 48-year-old first lady "underwent an embolization procedure to treat a benign kidney condition" on Monday, a statement from her office said.
"The procedure was successful and there were no complications," the White House said.
When asked how the first lady is feeling, a spokeswoman told ITK Trump "is doing well."
She will likely remain at Walter Reed National Military Medical Center the rest of the week.
CNN's Sanjay Gupta says that embolization procedures most often take place to remove cancer, though he pointed out that the statement said that the result was benign.
We'll have more details as they warrant and as they become available.