Puttaparthi: Sathya Sai Baba's condition has deteriorated further and his liver has stopped responding to medication.
Baba's liver and low blood pressure is also causing his doctors anxiety.
Breathing is still dependent on ventilators, haemodialysis was started on Thursday morning to assist the kidneys. But his body is not responding to any treatment.
"Non-functioning of the liver and persistent episodes of low blood pressure are causing great worry to the doctors," Dr AN Safaya, Director, Sri Sathya Sai Institute of Higher Sciences, said.
The doctors are putting their best efforts to improve his clinical condition, Dr Safaya said.
The 86-year-old religious leader was hospitalised on March 28. Meanwhile, security has been tightened at his ashram in Puttaparthi, as lakhs of devotees poured in upon hearing the news.
The Andhra Pradesh Police has been taking all precautionary measures towards maintaining security at Puttaparthi town and have deployed additional forces to maintain law and order.
Prohibitory orders were clamped in Puttaparthi on Thursday as thousands of devotees started descending on the town following reports that the condition of Sathya Sai Baba has deteriorated.
More than 2000 police officers and men have been deployed in Puttaparthi, particularly at the Sathya Sai Institute of Higher Medical Sciences (SSIHMS) where Sai Baba is undergoing treatment.
In Hyderabad, Director General of Police Aravinda Roa met Chief Minister Kiran Reddy and briefed him about the security measures put in place.
Shops in the vicinity of SSIHMS have been shut down as a precautionary measure, a senior police officer said.
Anantapur district Superintendent of Police Shahnawaz Qasim is personally monitoring the security arrangements.
To restrict the media coverage, power cuts have been imposed in Puttaparthi and trust members are intending to file defamation cases against media outlets.
(With additional information from Agencies)