Prime Minister Lee Hsien Loong's doctors have said he is okay after a thorough check-up, a day after he made many anxious when he faltered midway through Sunday's National Day Rally.
Mr Lee said he is taking doctors' advice to rest seriously, and will be on a week's medical leave.
Thanking rallygoers as well as Singaporeans for their concern and get-well wishes in a Facebook post, he said: "I'm sorry I didn't have the chance to meet you all after the Rally, as I went straight to the Singapore General Hospital (SGH) for a thorough check-up.
"I'm glad to report that the doctors think I am ok, but they have advised me to rest, so I will be on MC for this week."
The Prime Minister's Office (PMO) said in a statement that Mr Lee underwent a series of checks at SGH on Sunday night and yesterday morning, after he was taken ill while delivering his speech at ITE College Central.
Mr Lee, who was helped off stage, was attended to by a medical team on site that assessed his condition was not serious. In fact, while initial tests were being done, Mr Lee was busy re-editing his speech, Foreign Minister Vivian Balakrishnan added yesterday.
Mr Lee then returned over an hour later to complete his speech.
He had taken ill "due to a temporary drop in blood pressure, due to prolonged standing, exhaustion, and dehydration", the PMO said. "Doctors have confirmed there were no cardiac abnormalities and no stroke."
Mr Lee will resume his duties next Monday, and Deputy Prime Minister Teo Chee Hean will cover Mr Lee's duties during his absence, the statement added.
Mr Lee's sudden pause on Sunday night was widely reported by foreign media outlets, including the BBC, CNN, The Guardian and Xinhua news agency.
The update that Mr Lee is fine and recuperating drew relief from many Singaporeans yesterday.
"My initial thought was 'Oh no, not again'," Dr Balakrishnan recounted in a Facebook post, alluding to Finance Minister Heng Swee Keat's collapse from a stroke during a Cabinet meeting in May.
"And I am so glad it wasn't."
A medical doctor, Dr Balakrishnan said Mr Lee was fully conscious but sweating, and had a low heart rate and blood pressure during the spell. These are "classic symptoms" of a vasovagal episode, he added, referring to the condition when the body reacts to situations such as fatigue, dehydration or standing for too long, sometimes fainting.
President Tony Tan Keng Yam said he spoke with Mr Lee yesterday afternoon, and was glad to note that Mr Lee was well after his brief fainting spell at the Rally, and back to "his usual jovial self".
"PM had a busy schedule recently, and the preparation for NDR took a toll on him," said Dr Tan, using the abbreviation for the Rally.
"On behalf of all Singaporeans, I wish PM well," he added.
Mr Lee was originally scheduled to travel to Semarang in Central Java with a delegation of Singapore ministers tomorrow for the Indonesia-Singapore Leaders' Retreat with President Joko Widodo and his ministers.
That trip will now be rescheduled. A spokesman for the Ministry of Foreign Affairs said yesterday: "In view of PM Lee Hsien Loong's medical leave, the Indonesia-Singapore Leaders' Retreat has been postponed. Officials on both sides are working to find new dates for the Retreat."