Hardik, who is on the indefinite fast since August 25, agreed to be shifted to Sola Civil Hospital after his supporters requested him to so considering health condition.
The PAAS leader even stopped intake of water on Thursday evening after a 24-hour ultimatum he gave to the Gujarat government for talks had ended.
"Hardik's agitation will continue. But, since his health has deteriorated due to the 14-day fast, we requested him to get hospitalised," PAAS spokesperson Manoj Panara was quoted by PTI as saying.
Another PAAS leader, Dharmik Malaviya, said that Hardik's "fight will continue".
Hospital authorities said Hardik was in the ICU and a team of doctors was treating him.
He was shifted to the hospital shortly after senior Patidar community leader and president of Khodaldham Trust, Naresh Patel, met and advised him to call off the strike or take medical treatment.
Hardik went on the indefinite fast demanding reservations in government jobs and education for the Patidar community and waiver of farm loans. Later, he added another demand that his close aide Alpesh Kathiria, who was recently arrested in a 2015 sedition case by the city Crime Branch, be released.
The government had, in the last 14 days, not made any attempt to negotiate with Hardik, his supporters claimed.
(With inputs from agencies)