Princess Maha Chakri Sirindhorn, sister of King Vajiralongkorn, was admitted to the hospital on the evening of November 18 to treat coronary artery disease.

According to the Royal Thai home affairs agency, Sirindhorn was taken to King Chulalongkorn Hospital last night after the Princess's health care team found she had chest pain and an abnormal pulse.

A coronary image of the princess shows that the blood vessels to the heart have narrowed segments, but no surgical intervention is needed. Doctors suggested that Sirindhorn minimize participation in royal activities and stay in hospital for treatment.

Sirindhorn was born in 1955, the third son of the late King Bhumibol Adulyadej and Queen Sirikit. The Princess is the heir to the second throne after the Crown Prince in the Thai Royal Family.