Saudi Arabia's ageing King Salman entered hospital for "routine examinations" on Wednesday, the Royal Court said, in a rare public statement about his health.
The tests were taking place at King Faisal Specialist Hospital in the Red Sea coastal city of Jeddah and were expected to last "a few hours", the Royal Court said, according to the official Saudi Press Agency (SPA).
King Salman, 88, has been on the throne since 2015, though his son, Mohammed bin Salman, 38, was named crown prince in 2017 and acts as day-to-day ruler.
State media on Tuesday showed footage of King Salman attending a weekly cabinet meeting.
King Salman last entered the same hospital in Jeddah nearly two years ago, in May 2022, going in for a colonoscopy and staying for just over a week for other tests and "some time to rest", SPA reported at the time.
Saudi Arabia, the world's biggest crude exporter, has for years sought to quell speculation over King Salman's health.
In 2017, the Gulf kingdom dismissed reports and mounting speculation that the king was planning to abdicate in favour of Prince Mohammed.
King Salman underwent surgery to remove his gall bladder in 2020.
He was also admitted to hospital in March 2022 to undergo what state media described as "successful medical tests" and to change the battery of his pacemaker.
King Salman served as Riyadh governor for decades and also as defence minister.
His reign as king has been marked by ambitious social and economic reforms largely managed by his son, who is trying to position Saudi Arabia for an eventual post-oil future.
Prince Mohammed has also overseen an intense crackdown on dissent that analysts say has helped him consolidate power.