The South African anti-apartheid campaigner is expected to remain in a ward for a week or two, according to his family.
The 84-year-old Nobel Peace Prize winner underwent similar treatment last year, when he was in hospital several times.
Updated information will be released when it is available, said the archbishop's daughter, Thandeka Tutu-Gxashe.
He was the first black archbishop of Cape Town where he was an outspoken opponent of South Africa's apartheid regime, which enforced a harsh system of racial discrimination.
Since the end of apartheid in 1994, Tutu has campaigned for human rights, to fight HIV/AIDS, racism, sexism, homophobia and transphobia.
He also chaired the Truth and Reconciliation Commission that investigated atrocities during the apartheid regime and granted amnesty to some accused perpetrators.
