The Majlis-e-Ittehadul Muslimeen (MIM) leader fell ill while returning to Hyderabad from Nizamabad, where he appeared before a court Tuesday morning in a hate speech case.
Nizamabad is about 200 km from Hyderabad.
Owaisi complained of stomach pain and vomited on his way back to the city, said the doctor who was accompanying him. He was directly taken to the hospital
Courts in Adilabad and Nizamabad had granted him bail in two separate cases on Feb 14. After spending nearly 40 days in a jail in Adilabad town, he was released on Feb 15.
Owaisi, who is a member of assembly from Chandrayangutta constituency in Hyderabad, survived an assassination attempt in 2011. He, however, developed complications from bullet and stabbing injuries.