Sen. Dianne Feinstein is dealing with a health matter in her home state, a spokesperson said Thursday.

Feinstein's press office did not provide further details on the nature of the health matter or how it may impact her legislative work.

"Sen. Feinstein is in California this week dealing with a health matter. She hopes to return to Washington soon," the spokesperson said.

Feinstein, 89, announced last month that she will not seek reelection in 2024 after serving 30 years in the U.S. Senate. She is both the longest-serving female senator and the Senate's oldest member.

California's senior senator, who previously served as mayor of San Francisco, has been the subject of rumors about declining health and cognitive abilities.

Reps. Adam Schiff, Barbara Lee and Katie Porter are contending to replace her in the Senate when her term ends.