Updated

Thailand's 83-year-old King Bhumibol Adulyadej is recovering from a medical procedure to relieve a condition that made him walk unsteadily.

The Royal Household Bureau issued a statement Tuesday saying the king's temperature, blood pressure, heart and respiratory functions were normal after the 41-minute spinal tap procedure late Monday night.

A statement Monday said the king's condition — an excessive level of cerebrospinal fluid resulting in pressure on the brain — was common in the elderly.

Bhumibol entered Bangkok's Siriraj Hospital in September 2009 with a lung inflammation and has stayed since then except for infrequent short trips. The palace says he has remained in the hospital for physical therapy and nourishment to recover his strength.