He was first admitted to the emergency ward of the hospital and then shifted to the ICU.
"Anna complained of acidity, cough and weakness Friday morning and was admitted to Medicity Medanta here in sector 38," a close activist of Anna told IANS.
"He is stable and his heath is better. He is recovering. He has been kept in an ICU for some private reasons, not for his illness," said a senior doctor at Medanta.
Anna is scheduled to meet members of Anna Samanwaya Simiti from Haryana on December 9.
Anna, 75, was the face of the India Against Corruption movement, which was launched in December 2010 and united the poor and the middle class against corruption.