Google has shed more light on the health care service it is developing, showing off a couple of screenshots of what it will look like.

Google has been talking about its health initiative for some time now, slowly revealing more aspects of the project. Last week it announced a pilot of the service with the Cleveland Clinic in the US.

On 28 February, Google said that Google Health aims to offer users a central place to store their medical records. They will be able to import and share records from multiple institutions, provided the organisations already allow customers to digitally access their records.

A user's profile lists important information such as conditions, medications, test results, allergies and past operations. It also lists current doctors with their contact information.

Through the Cleveland Clinic pilot, Google has already discovered that the service is particularly useful to people who may live part of the year in one city and another in a second home, said Marissa Mayer, vice president of search and user products for Google, in a blog post. Those people have traditionally carried paper health records back and forth between the locations. Now they can import their data from each medical facility and share it electronically with the other facility.

Mayer stressed the privacy and security that Google will offer around customers' health data. Unless users give explicit permission, Google won't share or sell their data, she said. It has developed its privacy policy in collaboration with the Google Health Advisory Council, a group of medical professionals that offers feedback to Google on its health care product ideas and development.

Google is working on a directory of third-party services that will be accessible from Google Health. For now that simply allows users to import records into their profiles. In the future, Mayer wrote, it will let users schedule appointments and refill prescriptions online.

Despite Mayer's blog post and a speech on Thursday about Google Health by CEO Eric Schmidt at the Healthcare Information and Management Systems Society conference in Orlando, the service still isn't available beyond the Cleveland Clinic pilot. It should become publicly available in the "coming months," Mayer wrote.