Family doctors, nurses and other medical staff will be able to quiz patients on their sexual orientation under new Government plans.
Service users over the age of 16 visiting their local GP or hospital may be asked to confirm whether they are straight, gay, bisexual or other from 2019.
The NHS guidance apparently asks medical professionals to keep a record of the patient's answer during face-to-face consultations.
The health service said the move was to keep in line with equality legislation to ensure those who do not identify as heterosexual are treated fairly.
Individual NHS trusts will decide whether to opt out of the move, and patients will not be forced to answer.
An NHS England spokesman said: "All health bodies and local authorities with responsibility for adult social care are required under the Equality Act to ensure that no patient is discriminated against.
"This information standard is designed to help NHS bodies be compliant with the law by consisting collecting, only where relevant, personal details of patients such as race, sex and sexual orientation.
"They do not have to do it in every area, people do not have to answer the questions and it will have no impact on the care they receive."