Adopted family can check medical past
The relatives of adopted people will have more rights to find out about their birth family - so they can find out information such as inherited medical conditions.
The rules on sharing such information are being changed by the government to come into effect from November.
Relatives wanting to gather such information would use an intermediary adoption agency.
Families minister Edward Timpson said it was a "positive change".
A Department for Education spokeswoman said that the rule changes were about balancing the right of descendants of adopted people to know about their family history with the right to privacy for individuals.
It will mean that blood relatives of someone who has been adopted can ask for information about previous generations of their family, either living or dead.
This could reveal useful information such as genetic medical conditions or patterns of health risks, such as heart problems or types of cancer.
It could also lead to genealogical, family history information for the descendants of adopted people.
Where there is no contact with the birth family, or where a parent or grandparent does not want to be identified, information can be given anonymously, says the Department for Education.
Adoption agencies will be the contact points for requests and the sharing of information.
Such services are available to people who have been adopted, but this rule change will extend the right to the wider family, including grandchildren, partners and adoptive relatives.
Julia Feast of the British Association for Fostering and Adoption welcomed the plan.
"We are very pleased that the government has extended the rights of descendants and other relatives to access an intermediary service whilst ensuring that the adopted person's rights are not overlooked and will be at the centre of the decision making."
Mr Timpson said: "It's right that descendants and other relatives of adopted adults are able to access important information, such as medical records or genetic health conditions, which could impact upon how they live their life today.
"They should also be able to find out about important events from their past, as well as make contact with family members if they wish."
But it would still keep "important safeguards in place to protect the right to a private family life for those who were adopted," said the minister.