BANGKOK (AP) — Thailand's Queen Sirikit is being treated in a hospital for the flu, the royal palace announced Monday.

The announcement from the Royal Household Bureau said Sirikit was admitted to Bangkok's Chulalongkorn Hospital on Sunday with a fever and a cough and received medication. She was recovering but remained hospitalized on the recommendation of her doctors.

The mother of King Maha Vajiralongkorn Bodindradebayavarangkun turned 86 on Aug. 12. Her birthday is celebrated as Mother's Day, a national holiday in Thailand.

Sirikit is the widow of King Bhumibol Adulyadej, who died in 2016 after seven decades on the throne

She has been in ill health for several years, and is rarely seen in public, though photos were issued by the palace of family members visiting her on her birthday this month.