Ayelet Frisch said medics treated him at his home on Sunday night and detected a “light irregular heart rate”. She said the doctors decided he should spend the night in hospital for observation.
Peres was discharged from hospital last week after suffering a heart attack.
Peres completed his seven-year term as president in 2014. He remains politically active through his NGO, the Peres Center for Peace, which promotes coexistence between Arabs and Jews.
In a seven-decade political career, he served three stints as prime minister and won the Nobel peace prize in 1994 following the signing of the Oslo peace accords with the Palestinians.
Peres has filled nearly every position in Israeli public life since he became director general of the defence ministry at the age of 29 and spearheaded the development of Israel’s nuclear programme.
A protege of the country’s first prime minister, David Ben-Gurion, he was first elected to parliament in 1959. He has since held every major cabinet post and served three brief stints as prime minister in 1977, 1984 and 1995.