Essebsi was the world’s oldest sitting president. He was admitted to hospital on Wednesday but officials did not say why he was receiving treatment.
He won Tunisia’s first free elections in 2014 following Arab uprisings across the region.
Earlier this year, he announced he would not stand in elections expected in November.
Essebsi was also admitted to hospital last month after suffering what officials said was a “severe health crisis”.
They gave no further details. Tunisian Prime Minister Youssef Chahed, who visited him in hospital, urged people to stop spreading “fake news” about his condition.
Former Tunisian President Zine el-Abedine Ben Ali was ousted in 2011 after 23 years in office.
Since then, Tunisia has won praise as the only democracy to emerge from the revolutions of the so-called Arab spring.
Source: BBC
