Thailand's 88-year-old King Bhumobol Adulyadej, who has been in hospital for a year, has a swollen lung and knees and is recovering from a fever, the Royal Household Bureau said in a statement on Saturday.
The king has been treated for various ailments during hospitalisation in the Thai capital. He was last seen in public on Jan. 11, when he spent a few hours visiting his Bangkok palace.
The king has remained at Bangkok’s Siriraj Hospital since May 2015, when he was treated for a lung infection. He also suffered lung infections in 2009 and 2013.
Bhumibol's health has been watched closely in Thailand, where he is revered by many for what they say has been his unifying presence during a seven-decade reign marked by 16 successful or attempted coups and more than two-dozen changes of prime minister.
Under Thailand’s constitutional monarchy, the king is head of state while the prime minister and parliament govern the country’s affairs. Legislation must still be approved by the king.
Most Thais have never known life under another king. The designated successor is the king’s son, Crown Prince Maha Vajiralongkorn, 63, a career soldier.
News about the royals is tightly controlled in Thailand, where laws protecting the royal family from insult make it a crime to defame, insult or threaten the king, queen, heir to the throne or regent.
Updates on King Bhumibol's health are typically made public once he is recovering. The palace last issued a statement on his health three months ago.