"I am being treated for kidney related problems & certain infections that I have contracted," Jaitley said on Twitter.
"The future course of my treatment would be determined by the doctors treating me," he said in the tweet, adding he was currently working from a "controlled environment at home".
Jaitley, a prominent member of Prime Minister Narendra Modi's inner circle, went to Delhi's All India Institute of Medical Sciences for tests related to a kidney ailment, officials at the Finance Ministry and at the medical facility earlier told Reuters.
A medical report is due on Friday, one of the Finance Ministry officials said. They declined to be named because of the sensitivity of the matter and the Finance Ministry did not make any formal comment on the minister's health.
Sources at the Finance Ministry said Modi may have to appoint a minister as a replacement for Jaitley temporarily if he has to go on long leave for treatment.
I am being treated for kidney related problems & certain infections that I have contracted. I am therefore currently working from controlled environment at home. The future course of my treatment would be determined by the doctors treating me.— Arun Jaitley (@arunjaitley) April 5, 2018
Jaitley, 65, was due to meet Britain's finance minister Philip Hammond at the India-UK economic dialogue and deliver a talk on "Looking Ahead to 2022: India's Global Vision" at Chatham House, a policy think tank.
The organisers of the talk said the programme had been cancelled, without giving a reason.
"He will not visit London next week as he is not keeping well," one of the Indian officials said.