Princess Bajrakitiyabha, the 47-year-old eldest daughter of King Maha Vajiralongkorn, has experienced a serious deterioration in her health in 2026 caused by multiple infections, including a severe abdominal infection, the Royal Palace announced on May 21, 2026 [1, 2, 3].

The princess has remained hospitalized and in a coma since December 2022, when she collapsed during military dog training in Nakhon Ratchasima [2, 4, 5]. The coma and prolonged hospitalization have extended for more than three and a half years [2, 5, 6].

Doctors discovered in April 2026 that she had developed a severe abdominal infection linked to inflammation of her large intestine. This condition caused her blood pressure to drop and her heartbeat to become irregular [2, 3]. The resulting infections have spread uncontrollably and affected multiple organs, further compromising her condition [1, 3].

Her vital signs have been unstable, with low blood pressure, irregular heartbeat, and coagulation problems. She requires medical devices and medication to support her lung and kidney functions [1]. The Bureau of the Royal Household said, "Her condition has continued to deteriorate. The infection had become uncontrollable and affected other organs" [1].

Princess Bajrakitiyabha was educated in the UK, US, and Thailand and worked at the United Nations advocating for improved treatment of female prisoners [1, 7]. About a year before her hospitalization, she was appointed to a senior role in the King's bodyguard command [1].

King Maha Vajiralongkorn, 73, has been married four times and has seven children but has not publicly named an heir [1, 7]. The princess is his only child with his first wife [1].

The Royal Palace's May 21 statement said, "The princess's health has worsened due to severe abdominal infection and multiple organ dysfunction. Despite ongoing treatment, the infection remains difficult to control" [3]. Medical teams continue treatment, but her condition remains critical.

The princess remains in intensive care as doctors monitor her vital functions and infections closely following the latest health update.