It's mid-Tuesday morning at Bury Knowle health centre in Oxford and 74-year-old Ted East is sitting by a computer in the "information room". The retired police officer is discussing his part in a pilot trial which provides 100 patients with online access to their electronic health records via computers at the practice.

"There are times when you see the doctor frantically scribbling notes and you think to yourself, 'Hell, what's going in there? Is there some dark secret?' Now I know what's in my notes it's put my mind at rest and given me a sense of control."

Bury Knowle is one of two primary care groups in the country trialling the system. But within the next three years, every person in the UK should be able to gain access to their own "at-a-glance" electronic health record. Participants like East believe that they empower patients as never before. And some health professionals predict that they will revolutionise UK healthcare.

All patients have a legal right to see their records but few know that. What's more, the "doctor knows best" philosophy of the medical profession hardly encourages anyone to try. But the government's NHS Plan aims to ensure that patients take a more active role in managing their own healthcare. It is committed to providing everyone in the UK with their own electronic health record by March 2005. Which is why patients like East are currently spending as much time logging onto computers at their local surgery as they are consulting with GPs.

"I can see nothing but plusses to this," says East, who suffers from the rheumatic inflammatory disease polymyalgia. "One thing I've found is that it creates a two-way partnership between the patient and the doctor. For instance, it's often difficult to see the same doctor every time. But because I understand more about my condition and treatment, I can be more helpful to that doctor. I can say 'Look, you don't have to explain; I know my condition, I know what my blood pressure and sediment rate should be.' That saves the doctor time and they can be more open with you."

Patients use one of three PCs, each housed in booths fitted with curtains for privacy. They gain access to their records via NHS Net. To ensure security, fingerprint identification, date of birth and NHS number are required. To help patients who are non-computer literate each PC has a light point pen instead of a mouse for screen navigation. Once they're online, patients have limitless access to everything from their GP's scribblings to test results and consultants' letters.

"Patients do feel empowered by seeing their records," says Dr Cecilia Pyper, one of the GPs running the trial and a researcher at the Department of Public Health at the University of Oxford. "It makes them feel they're better able to ask questions, that there's less secrecy and they're more in control in terms of understanding what's going on with the management of their health. Our sort of motto here is 'Trust me, I'm the patient'. And that message seems to be filtering through."

Of course, some doctors could take umbrage at patients merrily rattling off information about their own conditions. And, some may feel patients are ill-equipped to understand the information they find.

"Well, that's a very patronising view I'm afraid," says Pyper. "There's a lot of very adult patients and what we've learnt from the research is that they can hack it. They can read a doctor's letter and work out complicated terminology."

To help patients "hack it", photocopied sheets are pinned to a wall in the information room listing all manner of medical abbreviations that patients may encounter as they scour their electronic records. These include NAD (nothing abnormal discovered), CO (complaining of) and HBD (has been drinking).

"I'm very interested in ensuring that these electronic records are validated; so that the doctor and patient both agree it's a totally accurate and comprehensive record," says Pyper. "For instance, a GP may interview a patient and miss out some key past history such as the fact that the patient had their appendix out while abroad. Only the patient would pick up on that."

There are other sound reasons for having access to your own medical records. East always takes his medical records on holiday with him. "Just so that, if you've got an ongoing condition like me and you're taken ill, the doctor would immediately have your record to hand."

This potential for patients or medical professionals to be able to tap into records, test results or x-rays from anywhere in the country or world is the holy grail of the NHS Plan. Unfortunately, there are still technological hurdles to be overcome with NHS Net.

Patient confidentiality and security of electronic patient records are also issues which need addressing according to the British Medical Association. "The problem at the moment is the confidentiality issue," says a spokesperson. "All the different parts of the NHS are not sufficiently encrypted and encoded up together at the moment."

Another problem could be patients' complete lack of enthusiasm for electronic health records. The Department of Health estimate that 5m people will have them by 2003, 25m by 2004 and the entire UK population by March 2005. All of which sounds impressive. But it's a safe bet that some people will be able to imagine nothing more yawn-inducing or terrifying than trawling through medical information about themselves.

Pyper, though, has no doubt that it is the way forward for healthcare in the UK. "Oh, it's the future of the NHS," she says. "It's the only way the NHS is going to be able to communicate effectively with consumers. And it's also the only way that we are going to be able to rebuild trust, optimise care and enable people to access information and self manage their health in a constructive way. It's our dream to offer it to all patients."

East has nothing but praise for the way electronic health records have helped him take control of his healthcare. If shown the real benefits of access, he says, most people would be in favour of it. "I can see only benefits flowing from all this. Because the one thing I can't emphasise enough is that this is your body. And if there's one person who should know what's going on in there it should be you."