It looks like an action-packed year ahead on the health front. Exciting new research projects will come to fruition, there will be more progress in treating cancer and heart disease, a new virus will scare us witless and we will get health advice from the television. Here's a guide to some of the health stories to look out for.

Bird flu

A big worry. Caused by a new strain of virus known as H5N1, it is affecting poultry in SE Asia and has started to cross over to humans. Experts are warning that a pandemic could affect between 7 million and 100 million people worldwide, with a mortality rate of more than 70%. The UK is better prepared than most countries but still has only enough anti-viral treatment for one third of the population.

Heart disease

Heart disease and cancer will remain the biggest threats to our health. Professor Peter Weissberg, medical director designate of the British Heart Foundation, says stem cell research will be big news next year.

Doctors are experimenting with taking bone marrow samples from people who have just had a heart attack and extracting the primitive stem cells that can transform into heart muscle cells. They want to squirt these stem cells into the damaged heart and see whether healthy, useful heart muscle will develop in its place. Some rather unconvincing research has provided lots of excitement but clinical trials run by a UK and European consortium are due to start in 2005 and their results will help to determine whether stem cell treatment after a heart attack will become routine.

Tiny pumps are being developed that can power failing hearts. Heart failure happens when the heart does not pump properly and fluid accumulates in the lungs, making the person increasingly breathless. Drugs are the only option at the moment - apart from a transplant, which is not suitable for older, weaker patients. But a small metal pump, known as LVAD (left ventricular assist device), implanted into the chest can take over the work of the heart. These are getting smaller as is the battery pack needed to power them.

A new screening test to detect heart failure is being investigated and could become widely available. A simple blood test can measure a chemical called BNP (beta naturetic peptide), which is released by a heart that is starting to fail. If the BNP is positive, the doctor will be able to order more specific and sophisticated investigations. If it is negative you can be reassured that your heart is still pumping well.

Hypertension

The treatment of high blood pressure is going to see some big changes. Beta blockers are going down and Ace inhibitors are going up in 2005. A trial published in mid-December compared people with high blood pressure taking losartan (an Ace inhibitor) with another group taking atenolol (a Beta blocker). The risk of a fatal stroke was 35% less in those taking losartan. Another major trial is due to present results at the American College of Cardiology in March. This trial has been stopped a year early after the discovery that a substantial number of people on perindopril (an ace inhibitor) and amlodipine (a calcium channel blocker) fared better than those on atenolol and a water pill. They had fewer non-fatal heart attacks and were less likely to die from heart disease.

Vitamin C might help too. Ten- year follow-ups of 300,000 people showed that taking 700mg/day of vitamin C cut the risk of heart disease by 25%. But vitamin E supplements didn't seem to have any impact.

Cancer

Professor Robert Souhami, Cancer Research UK's director of policy and communication, is optimistic about the future of cancer treatment and prevention. "We're being flooded with new drugs that need testing," he says. "It's a brilliant time to be in cancer research."

He says we're moving away from treating everyone with the same type and dose of treatment. By unravelling the biology and genetics of cancers, we can start to tailor prevention, detection and treatment to the individual. For instance, in treating breast cancer, the drug Herceptin may be effective if the cancer has the genes that code for a particular growth signal. But if your cancer doesn't have that growth signal, Herceptin is unlikely to work. Similarly, some lung cancers that have an epidermal growth factor receptor (EGFR) may respond to a drug called Iressa (also called ZD1839) that inhibits the EGFR. Our genes don't only determine whether our cancer will respond to a drug but also whether we're prone to side effects such as vomiting after chemotherapy.

There's going to be more interest than ever in the role of diet in cancer. The European Prospective Investigation into Cancer and Nutrition (Epic) is following up 400,000 healthy people to try to tease out what lifestyle and dietary factors affect cancer and death rates. And on a more practical note, look out for a new book by Royal Marsden Hospital's chief dietician Clare Shaw, called Cancer: The Power of Food, due to be published next year. It explores the evidence linking diet and cancer and provides lots of healthy recipes.

Complementary therapies

The popularity of complementary therapies is likely to continue to grow. Professor Edzard Ernst, director of the department for complementary medicine at the University of Exeter, looks forward to the results of American trials into herbal treatments, such as the effectiveness of Ginkgo biloba in preventing dementia in high-risk patients and the use of saw palmetto to shrink enlarged prostates.

Stress

Work stress will go right out of fashion as a study due out in 2005 will report on 1,381 people who had a non-fatal heart attack. Those who reported high stress levels at work including tight deadlines, conflict with colleagues and too much responsibility, were six times more likely to have a stroke in the next 24 hours than those who weren't stressed at work.

Painkillers

It will be a bad year for the group of painkillers known as Cox-2 inhibitors (eg Vioxx, Celebrex). Vioxx, which was widely prescribed for joint pains, has already been withdrawn because of an increased risk of heart problems. And a recent study into the use of Celebrex to treat cancer showed that the drug seemed to more than double the risk of non-fatal heart attacks. GPs are likely to take fright and advise patients to use paracetamol instead.

Acne

Doctors will be advising spotty teenagers and others with acne to buy cheap creams and ointments like 5% benzoyl peroxide which is available over the counter, rather than prescribing expensive and more risky oral antibiotics. A recent study has shown that benzoyl peroxide is 12 times more cost effective than the often-prescribed oral antibiotic Minocin and may work better.

Indigestion

Sufferers will be reassured in January by a study due to report that older patients with symptoms of indigestion who were referred by their GPs for investigation, were highly unlikely to have cancer. Older people with indigestion accounted for a fifth of all referrals for investigation into possible gastrointestinal cancer but only 0.3% of actual cancers found.

The doctors

GPs will come under scrutiny with the first of five-yearly revalidation checks led by the General Medical Council. Up to 11,000 GPs who care for around 3 million people in the UK are expected to be found unfit to practise. Meanwhile, the GMC itself will be challenging the government to retain its powers to discipline and regulate doctors. The GMC was heavily criticised in an inquiry into how Harold Shipman got away with murdering so many patients.

TV diagnosis

Ill people will be reaching for the remote in 2005 as NHS direct becomes interactive and moves to our TV screens. NHS Direct Interactive is already available to UK digital satellite viewers and will be rolled out to Freeview and cable users next year.

Every week will bring another health scare; prepare to read reports on the perils of mobiles, iPods, computers and killer bugs. But try to hang on to the fact that we've never lived longer or been in better health since the species began. Happy 2005!