Norway's Crown Princess Mette-Marit suffers from lung disease

The disease can cause serious breathing problems and there is no known cure.

Norway's Crown Princess Mette-Marit says she has a lung-scarring disease which may occasionally "limit the exercise of her official program."

Mette-Marit said that she has "had health challenges for several years" and has been diagnosed with an early stage of pulmonary fibrosis, in which scar tissue forms in the lungs.

The disease can cause serious breathing problems and there is no known cure.

Norway's future queen said in late Wednesday's statement by the royal palace that she would get treatments and further tests but gave no further details.

Matte-Marit, 45, made headlines in 2001 when she married Crown Prince Haakon because she was a single mother who had lived a freewheeling life with a companion convicted of a drug offence. The couple has two children together.