AdvertisementAdvertisementPrincess Bajrakitiyabha Mahidol of Thailand. (File photo: AP/Ronald Zak)21 May 2026 12:31PM (Updated: 21 May 2026 12:37PM) Bookmark Bookmark WhatsApp Telegram Facebook Twitter Email LinkedInAdd CNA as a trusted source to help Google better understand and surface our content in search results.Read a summary of this article on FAST.Get bite-sized news via a newcards interface. Give it a try.Click here to return to FAST Tap here to return to FASTFAST BANGKOK: The health condition of a Thai princess who has been hospitalised for more than three years has deteriorated, the palace said Thursday (May 21).Princess Bajrakitiyabha Mahidol, the king's eldest daughter, fell ill during a military dog training session in December 2022 and has remained in hospital since.She suffered from a severe blood infection and her lung and kidney functions were being supported by medical devices and medication, the palace previously said.The Bureau of the Royal Household said in a statement on Thursday that the princess had developed an abdominal infection from inflammation of the large intestine and was experiencing "unstable vital signs, low blood pressure, irregular heartbeat and abnormal blood coagulation".Show MoreShow LessThe palace added that Bajrakitiyabha was still relying on medical equipment to support her lung and kidney functions, as well as medication."Her condition has continued to deteriorate," it said, adding that the infection had become "uncontrollable and affected other organs".Educated in Britain, the United States and Thailand, Bajrakitiyabha held several positions with the United Nations and campaigned for better treatment of women in prisons.Known in Thailand as "Princess Bha", the 47-year-old is the only child from King Maha Vajiralongkorn's first marriage.She is seen as close to her father, and was appointed to a senior role in his bodyguard command a year before her hospitalisation.The 73-year-old king, who has seven children from four marriages, has not announced his chosen heir, though succession rules favour men.Thai king's eldest daughter Bajrakitiyabha warded in hospitalCommentary: The heirs and spares of Thailand’s monarchySource: AFP/coNewsletterMorning BriefSubscribe to CNA’s Morning BriefAn automated curation of our top stories to start your day.Sign up for our newslettersGet our pick of top stories and thought-provoking articles in your inboxSubscribe hereGet the CNA appStay updated with notifications for breaking news and our best storiesDownload hereGet WhatsApp alertsJoin our channel for the top reads for the day on your preferred chat appJoin hereAlso worth readingContent is loading...Expand to read the full storyGet bite-sized news via a newcards interface. Give it a try.Click here to return to FAST Tap here to return to FASTFAST