BANGKOK (AP) — Doctors have advised Thailand's King Bhumibol Adulyadej to rest after he suffered from a mild fever for a week.
The Royal Household Bureau said in a statement Tuesday that the 85-year-old king also had little appetite and was weak.
It said daily physical checkups showed the monarch was breathing slightly faster than normal.
The palace said the king suffered pain in his knees on Tuesday and doctors found they were swollen.
It said blood tests showed he did not have any bacterial infection.
The palace added that doctors have advised the king to refrain from his official duties for a while.
Bhumibol, the world's longest-serving living monarch, entered Bangkok's Siriraj Hospital in September 2009 with a lung inflammation and has stayed there since then except for infrequent short trips.