Sonia Gandhi, who married into India's Nehru-Gandhi family and serves as president of the ruling Congress party, was taken to the hospital after falling ill during a vote on amendments to a food security bill Monday.
Gandhi left Parliament in the evening with her son Rahul Gandhi, Congress' vice president, by her side, and was taken to AIIMS hospital in New Delhi.
Though it's not clear what caused the political leader to fall ill, doctors said she complained of chest pain and a headache.
"Mrs Gandhi had cold and a headache. She had a medicine and started feeling uneasy in Parliament. She came here, we conducted tests... everything is normal. She left for home in her own car," an AIIMS doctor told reporters.
The 66-year-old politician had championed the food security bill as a step toward eliminating hunger in India.