She was quickly rushed to hospital by her family after falling ill. The incident was reported by Asian News International (ANI) in a tweet on Tuesday evening.
A number of party colleagues and ministers, including Nitin Gadkari, Dr Harshvardhan, Rajnath Singh and Smriti Irani arrived at the hospital to visit and pay respects following her passing.
Indian President Narendra Modi also paid respects on Twitter saying "A glorious chapter in Indian politics comes to an end."
Worrying signs began in the 2019 Indian elections, where the 67-year-old did not contest the Lok Sabha election in and did not join Prime Minister Modi's new government. Despite this, the party still won a significant majority in the election.
There was outpouring of condolences for the former leader online, describing her as a prominent representative of women in Indian politics.
A nine-time parliamentarian, Sushma Swaraj became the youngest minister of any state when she was elected in Haryana in 1977.
She also served as the chief minister of Delhi as well as health secretary for the Atal Bihari Vajpayee government.
She became the second women to hold the office of foreign minister since Indira Gandhi when she was appointed in 2014.
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