Todd C. Frankel writes at the Washington Post that Democratic presidential nominee Hillary Clinton has been extremely private about a variety of maladies she’s incurred since 1998 including three blood clots, the last of which afflicted her skull in 2012.

When it comes to personal health, Hillary Clinton has long opted for intense privacy, dating back to 1998 when she experienced what she later described as her “scariest moment” with a blood clot in her right leg.

At the time, President Bill Clinton’s White House said little about the first lady’s medical emergency, discreetly treated as an outpatient at Bethesda National Naval Medical Center. Hillary Clinton, who told the White House physician then that she was too busy campaigning for Democrats to be admitted to the hospital, later described the incident as “the most significant health scare I’ve ever had.”

Doctors found a second clot in her legs in 2009, a fact not widely known until her Mount Kisco, N.Y., internist released a letter in July 2015 attesting to her good health as she launched a campaign for the Democratic nomination for the presidency.

Clinton’s third blood clot in 2012 — this time in her skull — was too serious to keep under wraps, since she was serving at the time in a high-profile role as President Obama’s secretary of state. She spent several days in New York-Presbyterian/Columbia University hospital, and her husband later said it took her six months to recover.