SINGAPORE, Aug 22  — Prime Minister Lee Hsien Loong’s medical tests at the Singapore General Hospital this morning were “all normal”, Foreign Minister Dr Vivian Balakrishnan has disclosed.

In a Facebook post at 9.55am, Dr Vivian gave fresh details about Lee’s brief health scare last night, when he became unsteady during the English portion of his annual National Day Rally (NDR) speech.

Lee was seen clasping the sides of the lectern before several people rushed to his aid and escorted him off the stage.

“When we rushed up on stage, we found PM Lee fully conscious but having classic symptoms and signs  — sweatiness, low heart rate and low blood pressure,” the minister wrote, noting that Lee had a “vasovagal episode”, the medical term for fainting.

Dr Vivian added: “The initial light headedness resolved within minutes, and I knew he just wanted to get back on stage to complete his speech.... We then went to SGH for more tests  — which were all normal before calling it a night around 1.30am.”

Lee headed for the hospital for a medical check up after returning to the stage at the ITE College Central to conclude his NDR speech .

There was an 80-minute interruption to the live telecast, between 9.20pm when Lee took ill, and 10.40pm when he returned to loud cheers and a standing ovation.

Other ministers who were on the scene with Lee described his condition as “not serious”, but urged him to take more rest.

However, Lee, who has an active presence on social media, was still awake at 2am today as he responded to a get-well message from his Malaysian counterpart Datuk Seri Najib Razak.

“@NajibRazak Thanks for your good wishes. My doctors tell me I should be OK. - LHL,” Lee wrote on Twitter, signing off with his initials.

The Prime Minister’s Office (PMO) said last night that Lee had felt unsteady from “prolonged standing, heat and dehydration”.

“His heart is fine and he did not have a stroke,” the PMO added.

Still, yesterday’s episode was a bad case of deja vu for Cabinet ministers like Dr Vivian, who witnessed another colleague’s health scare up close recently.

In May, Finance Minister Heng Swee Keat collapsed during a Cabinet meeting after suffering a stroke. He has since recovered and will resume his duties progressively.

“My initial thought was ‘Oh no, not again,’” Dr Vivian wrote.

“And I am so glad it wasn’t.” — TODAY