The 89-year-old Sen. Dianne Feinstein, D-Calif., caused concern by missing a Judiciary Committee hearing this week. On Thursday, her spokesperson cited an unspecified “health issue” as the reason for her absence.

Now, Feinstein’s office is giving details.

Feinstein — the oldest member of Congress — disclosed Thursday that she has been hospitalized in San Francisco and is being treated for a case of shingles.

The six-term senator said in a three-sentence statement released by her office that she was diagnosed last month and expects to make a full recovery.

“I was diagnosed over the February recess with a case of shingles. I have been hospitalized and am receiving treatment in San Francisco and expect to make a full recovery. I hope to return to the Senate later this month,” Feinstein said in a statement obtained by Reuters.

According to the Mayo Clinic website, shingles is a viral infection that causes a painful rash, which can occur anywhere on the body. The illness usually presents in seniors who contracted chickenpox when younger.

The illness isn’t life-threatening, and early treatment can reduce the risk of complications.

Feinstein, who took office in 1992, recently announced she would not seek reelection in 2024. The senator has faced questions in recent years about her cognitive health and memory, though she has defended her effectiveness.

“The real question is whether I’m still an effective representative for 40 million Californians, and the record shows that I am,” Feinstein said last year, according to CNBC.

Even so, Feinstein has been stepping back from her senatorial duties. Last year, she declined to serve as the Senate’s pro tempore president, a role usually handed to the most senior senator in the ruling party.

In 2020, she resigned from her post as the top-ranked Democrat on the Judiciary Committee, following her controversial remarks during a Supreme Court confirmation hearing.

Thursday flashback! Dianne Feinstein, 89, missing work due to ‘health matter’

The Horn editorial team and the Associated Press contributed to this article.