Dr. Moshe Daniel, the hospital's deputy director, told Ynet that the rabbi was being examined at the emergency room and will be hospitalized.
The rabbi's condition was defined as light and stable.
Rabbi Yosef's personal doctor, who lives in Jerusalem, was making his way to the Nahariya hospital in order to examine the rabbi and aid in his treatment.
The rabbi was on his way to a rally in Akko. During his visit to the north, he complained of chest pains and was immediately rushed by ambulance to the Nahariya hospital for a series of tests.
The rabbi was accompanied by Shas Chairman Eliyahu Yishai, the party's director Yakov Margi, and other officials.
The rabbi's associates said that he was fully conscious after suffering a heart attack. Shas members were attempting to arrange for a helicopter to take the rabbi to a hospital in Jerusalem, but in the meantime it appears the rabbi will be forced to remain at the Nahariya hospital.
Rabbi Yosef, 86, is the father of 11 children.