University of Maryland Professor Steven Soifer wants to talk about a health condition that most sufferers don't want to talk about.

It is a condition that 20 million people in the United States and Canada have, to one extent or another, according to a 1997 Harvard Medical School survey. And many "feel completely isolated and think they're the only person in the world with the problem," Soifer says.

One million to two million people have the problem so bad it affects how they live,

The problem is Shy Bladder Syndrome, or parauresis. It's when someone finds it difficult to urinate in public restrooms, or even at home, if other people are around. The cause can be partially biological, partially environmental and partially psychological. A critical or traumatic event at any stage in life can trigger the condition.

"Some people have a pro- pensity toward it, and a trauma will bring it out in one trial running," Soifer says.

These traumas may include a bad experience during toilet training, at school, during puberty, or even in adulthood -- one man in Boston did not develop the disorder until his late 40s. The origins are different from person to person, but most people who suffer from it have a biological vulnerability to it, Soifer says.

Research has shown that people with one or more parents who show signs of the disorder are about 30 percent more likely to suffer from it than those whose parents show no signs. In the most extreme cases, which account for about 7 percent, the sufferer finds it impossible to use the bathroom in the presence of others.

Soifer, associate professor of social work, says the effects of the problem can range from causing a person to avoid social activity and travel, to full-blown agoraphobia, where an individual will become homebound to avoid the problem.

Methods of treatment include what Soifer calls "graduated exposure therapy," which desensitizes parauresis sufferers to their fear of public urination.

Soifer is himself recovering from the disorder. Though he's much improved, he says a bad day can trigger his symptoms. He says that if a sufferer works on his or her condition, they will see progress. Soifer adds, "I'm not bold enough to say there's a cure. It's a process."

If you need help ...

Professor Steven Soifer has founded a support group that deals with and helps treat Shy Bladder Syndrome: the International Parauresis Association, which can be reached at 800-247-3864.