When Colin Osborne found a lump on his testicle, he took no notice. He allowed the lump to grow. It started to hurt when he leant against his desk, but still he ignored it. According to new research, there was nothing abnormal about his response - he was simply doing what most men do when faced with a health problem. 'I'm not one to go to the doctor's,' Colin says. 'When I have a cold, I never take anything. The lump didn't bother me. I didn't discuss it. I thought it would go away. I have to be at death's door before I stop what I'm doing.'

Colin, then aged 32, was at death's door, only he didn't realise it. By now two months had passed and Colin's wife Sandra begged him to visit his GP. 'I said: "No, I'll leave it a couple of weeks."'

Sandra made an appointment. Within two weeks everything had changed. Colin had testicular cancer. The cancer had spread to his lymph nodes. The surgeon reckoned the disease had been there for six months. Colin endured a gruelling regime of surgery, chemotherapy and a bone-marrow transplant.

He suffered side effects, including a stroke and septicaemia. Had he sought help earlier, the condition would have been less advanced and the treatment less harsh. Dr Ian Banks, president of the Men's Health Forum, which promotes men's health, described Colin's attitude as 'typical'. More women than men get a malignant melanoma, yet more men die from it. The only explanation for this is that men seek medical help far too late. In fact, men are more likely to suffer premature death over all conditions that affect both sexes.

The General Household Survey reveals that men consult GPs less often than women. In 2002 only 13 per cent of men saw a GP, as against 17 per cent of women. According to health psychologist Dr Sarah Grogan, who interviewed 115 men, wives and GPs on their health attitudes, men do not see health as a 'male' pursuit. Grogan, who presented her findings at a recent British Psychological Society conference, explained: 'Being ill was viewed by the men as shameful and "unmanly". Men are trained to be stoical and John Wayne-like.' And the men in the study delegated their day-to-day healthcare to their wives, viewing this as an extension of the nurturing role that women have. Alan White, professor of men's health at Leeds Metropolitan University, believes men relinquish control of their health at every stage. 'They give this role to their mothers and then their girlfriends, wives and sisters.' The message begins early - usually the mother takes the child to the doctor's.

At school, peer pressure among teenage boys ensures that health concerns are not aired. A survey of 16-year-old boys found that almost none had ever made a doctor's appointment. 'The attitude continues into manhood. If you go into a pub and admit to having emotional problems or something wrong with your testicles, the reaction will be very negative indeed,' says White.

Experts claim the media exacerbates the problem. When Tony Blair had chest pains, there were headlines asking: 'Why hasn't Cherie done more?' And women's magazines run articles entitled: 'Is your man eating properly?'

'There is a lot of social pressure on women to take responsibility for men's health. It is absolutely unreasonable, especially when women have responsibility for their own, their children's and sometimes their parents' health,' says Grogan.

And she warns that both women and health professionals 'collude' by encouraging men to see health as a female domain. The way the NHS is set up compounds the problem. Women access it for contraception advice, cervical screening and help with childbirth. But there is nothing in the new GP contract that requires the screening of men. As a result, men don't know when to consult, or fear that their condition is not severe enough to prompt investigation. Consequently, they devolve responsibility to their partners.

Experts realise that if men are to become more responsible, then the health service needs to become more male-friendly. The Men's Health Forum is piloting schemes in which poster campaigns and talks take place in the workplace and at gyms, pubs, football grounds and barber shops. Banks has also published a series of health guides laid out in the style of the Haynes car manuals and sold in Halfords, among other manly outlets. The Forum is also urging pharmacists to have more man appeal. Simple tricks such as placing gadgets by the counter can make a difference. White says mobile health centres, a five-yearly health-screening programme and more access to health services via the internet would also help. In addition, he says boys need to be taught to take control of their own health from the start. Colin Osborne has taken this message on board and set up the Orchid Cancer Appeal, which distributes the Know Your Balls - Check Them Out video to schools.

And boys would do well to heed the message, because the tide is turning. Currently one in 15 men aged 35 to 44 lives alone. This rises to one in five among the over-65s. By 2020 one in five of all men will be by themselves. If men do not take responsibility for their own health, the cost will be high indeed.

'What was OK in the past may not be OK in the future,' warns White. 'Men must become more sophisticated at managing and monitoring their own health. After all, whose body is it anyway?'

· The Orchid Cancer Appeal can be reached on 020 7601 7808; orchid-cancer.org.uk. Also visit menshealthforum.org.uk. The Haynes Owners Workshop Manual series includes 'Man', 'Baby', 'Sex' and 'Cancer' by Dr Ian Banks (£12.99 each, Haynes Publishing)