This is the story of a woman whose effort to join a health plan led to a frightening misadventure.

There's a lesson in it for anyone who has to battle a bureaucracy. There is also an embarrassing lesson for the health plan, one which did hve some laudable intentions.

Early last December Maggie Hillis, a self-employed Washington woman, decided to join the George Washington University Health Plan, which offers individuals "your complete healthcare system" -- doctor care and hospital care -- for $88.96 a month.

She sent in her application and in time was summoned to its headquarters for a physical examination. Her examiner there last Jan. 2 was Dr. Herman Pettiford, the plan's chief of medicine.

"He used a stethoscope," she remembers, "and never said a word to me" about any problem, just " 'Have a nice day, goodbye' when he was finished."

Then "several days went by and I still hadn't heard anything. I kept calling them, I must have called five, six times, but they always said, 'We haven't got the report back.' Finally on Friday, Jan. 17, I got a form letter."

The form letter said: "We have carefuly reviewed your application and regret to inform you that your application . . . did not meet the criteria for acceptance. Thank you for your interest . . ."

She had no idea why she was rejected. Naturally she was worried.

That Monday was a holiday, but on Tuesday she phoned the plan and was told, "Dr. Pettiford will write you."

Late that week she still had heard nothing. And that Friday afternoon, Jan. 24, a friend of hers told me, "She's on pins and needles sweating it out, wondering if she has some horrible disease."

I phoned Ron Davey, the plan's executive director, to ask about the case. He said he'd try to reach Dr. Pettiford.

Pettiford did now phone Hillis. He apologized for the delay, and finally told her why she had been rejected. The problem, he explained, was that he had detected an abdominal bruit. Pronounced "broo-ee," a bruit is a sound or murmer from within the body, often made by the bloodstream rushing through some unusual or abnormal area in a blood vessel.

"I kept asking him, 'What does it mean?' " Hillis says. "He said it might mean something and might not mean anything, and the only way to know for sure was to have an ultrasound examination performed at my own expense."

Later that morning she also got a call from Dan Sullivan, the plan's director of member services. "I told him that I thought I'd gotten a runaround, and that it was a terrible way to tell me something might be wrong."

Actually, she might have added, she might never have known what was wrong had she not persisted.

"Sullivan," she says, "also told me they were holding a meeting of their top administrators that morning to review their procedures. So I was glad I stuck with it."

There was indeed such a meeting, and one result was a revised form letter that henceforth would tell anyone who was rejected that: "This decision is based upon a review of your previous records and/or pre-existing medical conditions. Please be assured that this decision is not to be construed as indicating any findings about your health beyond the information you have provided. If . . . any new or serious problem had been noted . . . you would have been notified."

Under this new procedure, Maggie Hillis presumably would have been told about the noise that Dr. Pettiford heard through his stethescope.

What of that bruit, however? What did it really amount to?

She phoned a downtown doctor who told her he'd be glad to examine her, but thought she ought to try going back to the health plan. "I thought their behavior was wrong," that doctor told me. "If a physician undertakes an examination, that establishes an obligation to a patient. If you find something, you can't simply say, 'We found something, but we're not going to pursue it.' "

At this point, however, reports Pettiford: "We did offer her a free ultrasound." And, says Sullivan, "I told her that if the result was negative, we'd be glad to reconsider her application."

She did have the free ultrasound. It was negative. In other words, she was healthy. But she did not then join the George Washington Health Plan. Instead she joined Kaiser.

Looking back, Davey, the GW executive director, says, "Quite frankly, I thought we didn't handle it as well as we could have."

But Pettiford, says Dr. Jack Ott, the plan's medical director and Pettiford's superior, did not act without logic. "What he heard was the blood burbling as it was flowing. That could mean one of several possible abnormalities, or it could be physiologic, like a heart murmur without heart disease. In other words, it could have been normal, it could have been abnormal. But this particular bruit could not be considered normal until proved otherwise."

The problem might not have arisen, Ott adds, were it not for "our plan's attitude, our desire to increase the number of patients who could be eligible, those who now have trouble getting adequate health insurance.

"A self-employed person or someone who doesn't belong to a group usually has a hard time buying health insurance. If there is any pre-existing condition, they're usually not covered or not covered for a period of time.

"Starting last November, we set up a new program in which we felt that by a little more careful screening, we could in fact take many people who otherwise might not be eligible. For example, some other plan might turn down a person with borderline hypertension. But by our physical examination, we might decide we could take this person. We really saw this as a community service.

"In the case of Miss Hillis, she was called in for a physical examination because she reported having some surgery within the previous two years." So again, he adds, "we wanted to see if we could accept her."

The George Washington plan deserves credit for indeed trying to extend crucial health coverage to persons who might not otherwise be able to get it. It deserves credit for acting without delay to reexamine its procedures when it recognized a problem.

The question nonetheless remains: What is the obligation of any physician, whether doing a "insurance physical" or not, as soon as he or she encounters a possibly perilous condition a patient should know about?

Shouldn't the patient be told, without delay?

Dr. Ott maintains: "What we followed is the standard that is usual in the insurance industry. If you have a physical examination for life insurance, you aren't informed of anything if you're turned down. You're just informed you don't qualify -- unless there's a life-threatening situation."

That's just the point in this case. Hillis just might have had an aneurysm, or weakened place in her aorta, the main blood vessel that carries newly oxygenated blood from the heart down through the trunk.

That indeed could have been life-threatening. And she would not have know about it if she had just accepted her rejection without persistent inquiry.