Queen Mette-Marit was taken to the National Hospital in Oslo on Tuesday night by her husband, King Haakon. The 53-year-old Queen Consort, who pulled out of her husband's swearing-in ceremony at the last minute, was driven to the hospital due to a medical emergency. The exact reason for the specific visit has not been confirmed, but an earlier statement from the Norwegian Palace said she needed to be observed. Her last-minute decision not to attend the historic event suggests she had a medical emergency after her health deteriorated.

Mette-Marit was expected to attend her husband's official oath to the constitution, with their daughter, Crown Princess Ingrid Alexandra, standing in for her. King Haakon is taking part in the official steps to take over as monarch after his father, King Harald, breathed his last on Friday at the age of 89. He had ruled Norway for 35 years.

On Monday, Mette-Marit's doctors gave an official update on her condition, saying her absence was due to complications from her lung transplant, which she received in June. Pulmonologist Are Holm at the National Hospital said it is not uncommon for complications to occur after a lung transplant, adding that the Queen has had complications on some occasions since the operation.

The palace did not give further comment after the royal couple arrived at the hospital. The Queen has suffered from a rare form of pulmonary fibrosis since 2018. Earlier this year, Haakon revealed that her condition had worsened and she was seriously ill before undergoing her lung transplant.