The hospital in a statement said there was a drop in his blood pressure and it was stabilised with treatment. He remains in ICU and continues to be treated by a panel of expert doctors.
Several senior DMK leaders, including working president M K Stalin and his elder brother M K Alagiri were at the hospital.
Party cadres had poured in near the hospital complex after receiving the news about Karunanidhi being admitted there.
Tamil Nadu Governor Banwarilal Purohit also visited Kauvery hospital and inquired DMK Supremo’s health.
Defence Minister Nirmala Sitharaman also visited the hospital and enquired about his health.
Tamilnadu Chief Minister Edappadi K. Palaniswami, in a statement says the government is willing to provide all medical help to Karunanidhi, if it is sought. he notes that he was a five-time Chief Minister and had ruled the State for long.