Norway's King Harald V left hospital on Monday, three days after he was admitted due to breathing difficulties, the royal palace said.
Oslo University Hospital would continue its assessment. Shortly after the king was admitted to hospital on Friday, the palace said that he did not have Covid-19.
The king would be on sick leave until October 4, and will miss out on Friday's state opening of parliament.
Crown Prince Haakon would attend the opening as would Queen Sonja. The crown prince also chaired Friday's regular state council session with the Cabinet.
Harald became king in 1991.
In December, Harald cancelled a few engagements due to a viral infection, but gave his annual New Year's speech as scheduled. In early January, he spent a week in hospital after suffering from dizziness.
The king underwent heart surgery in 2005 and at the end of 2003 was operated on for bladder cancer. Both procedures were described as successful.
In November 2017, the king was also briefly hospitalized for an infection.