An investigation into how well the £5.5bn private healthcare market is working is being planned by the Office of Fair Trading (OFT).
It will examine the nature of competition in the market, as well as whether it is fully competitive.
The OFT said its preliminary research had raised questions about whether the market was working well for private patients.
It aims to formally launch its investigation in spring next year.
Meantime, it is seeking views on the proposed scope of the study.
The OFT says the private healthcare market is of growing importance due to an ageing population, improved medical outcomes and higher life expectancy.
It added that it was of growing importance to the NHS because of government initiatives that allow NHS patients to seek treatment from private healthcare providers in certain circumstances.
Sonya Branch, OFT senior director of services and public markets said: "We are keen to focus on whether patients and buyers of private healthcare, including the NHS, are getting the full benefit of choice and competition."
She added that as the area was a complex one, the OFT would be speaking to providers, patients and government to make sure that it focussed on the correct issues.