Sonia's last major public engagement was Varanasi road show
She had suddenly taken ill during the road show in Varanasi on August 2 and had to return to the national capital.
She was later admitted to a private hospital in Delhi following dehydration and fever. She also underwent treatment for a shoulder injury.
After falling ill at Varanasi, Gandhi's first major official interaction was in October, when she met visiting Sri Lankan Prime Minister Ranil Wickremesinghe. Later in the month, she also met visiting Myanmar State Counsellor and Foreign Minister Aung San Suu Kyi at her residence.
Gandhi on Monday reported unwell ahead of the party's working committee meet that she was scheduled to chair. Sources said she complained of a bad throat.
There have been demands in the party that Congress Vice President Rahul Gandhi take over the reigns of the party from his mother amid concerns that Sonia Gandhi should not undertake a strenuous election campaign for the upcoming assembly polls in five states.