Professor Alan White, of Leeds Metropolitan University and chairman of the Men's Health Forum, said there was a need to find out why diseases which should affect men and women equally, hit men more.
In his inaugural lecture, he said men had a higher incidence of nearly all cancers and a greater chance of early death but there was still no explanation for this.
There were also huge inequalities in men's life expectancy between different areas of the country – 66 years in parts of Leeds, less than many parts of Eastern Europe, and 79 years in nearby Wetherby.
"By generating a better understanding of how men experience their health and illness we may be better able to target men more effectively," he said.
A four-year study involving health workers in Bradford and Keighley had found that men only went to the doctor when they felt they were "poorly" and were unwilling to "bother" doctors.
But when a health team set up clinics in work places and pubs, and staged events at football grounds men asked for information.
The biggest cause of death among men under 44 was suicide, he said, but in a study of 200 people who had taken their own lives in Leeds, 43 men had shown no signs of illness or distress, indicating they felt suicide was the only way out.
He said it would take national action to fund research into masculinity and social pressures faced by men.
"It does matter that coronary heart disease, mental health problems and diabetes are very different problems for men and women," he said.
"There are serious concerns about the state of men and their health and it is beholden on us to ensure that we take whatever steps can be taken to tackle what could be the biggest issue of the 21st century."