Most of us have a hard time getting up the courage to complain to our doctors. I have a doctor I like. Yet every now and then I feel like saying, "Why didn't you do such-and-such?" I seldom say it.

Why not?

"Patients are afraid to say they don't understand or to question what we're doing," says Dr. Robert Collins, a Washington orthopedist. "They'll often complain to our staff. Then when they come in to see us, they'll say nothing or, if the subject comes up, 'Oh, it's all right, doctor.' "

"They don't want to make the doctor angry," says Dr. Norman Lee Barr, a Washington ear, nose and throat specialist.

"It's a real problem, it's a human problem," says Dr. Devra Marcus, a Washington internist. "It's not easy to be critical of anybody.

"There's also an authoritarian quality to physicians, no matter how easy we are to talk to. The patient needs to feel the doctor is trustworthy, and one way the physician makes the patient feel that is to take on an authoritarian quality. It's hard to question an authority. It's really tough for people to be critical of people they're dependent on."

But by remaining silent, we may do serious harm to the chance for a healthy doctor-patient partnership, as well as potentially harm our own health. By saying nothing, we also tell the doctor, "Everything's okay," when maybe it isn't, or "I understand," when maybe we don't.

We make it even harder to speak up in the future. And by giving our doctor the wrong kind of feedback, by in effect saying, "Your behavior is right," we help create a physician who hides from all patients behind a wall of hard silence.

"Many a patient leaves the doctor's office with reservations about the prescribed treatment," says Harvard University's Dr. William Stason. "But the doctor knows nothing about them because the patient has smiled and said, 'Thank you.' "

The cure? "Next time you visit your doctor, don't dummy up," the American Society for Internal Medicine advises in a series of TV spots addresed to potential patients.

The best way to speak? "Just speak up -- just tell us what's on your mind," many doctors say.

"I think the best way to complain," says orthopedist Collins, "is just to do so right away." Waiting often magnifies problems. When a problem becomes big enough, repair may be impossible.

Sometimes anger needs to be expressed, even to a physician. As a human being and as a patient, you have a right to be angry when anger is appropriate. To build a good relationship with your doctor, however, speak up, if you can, before anger is necessary.

What can you say? Various doctors and patients suggest phrases like: "I have a problem with what you're doing, and I'd like to work it out." Or: "I'm uneasy about something." Or a statement sure to arouse any good doctor's instincts as teacher: "I really don't understand what you're doing."

If a fee seems high, ask for an explanation. That can give you a chance to say it seems too steep. If a name-brand drug is prescribed and you want to buy a cheaper generic form, say so. If a doctor hasn't answered your phone calls or keeps interrupting your visit to take calls, or you feel you've been hurried, you have a right to say, "I don't feel I'm getting through to you." One doctor even reports, "My patients occasionally say, 'Are you really listening?' "

Above all, many doctors say, if you don't understand everything about a doctor's directions or explanations, say so. It could save your life.

"If you're hesitant or you want some time to go home and think a bit," Dr. Barr suggests, "write us a note and say you're unhappy or you have some questions."

Why is all this necessary? Most doctors don't know that they have offended or puzzled you. The best ones welcome criticism, though like all human beings they might not always like to hear it.

Some doctors, unfortunately, never like to hear it. There are physicians, just as there are other persons, who cannot bear criticism -- or even questions. They consider all questioning a threat to their self-image. And sometimes their lack of self-confidence may be justified -- these doctors may indeed not be very competent.

As a patient dealing with these problems, you have to set some priorities, Dr. Marcus points out. "If a doctor isn't giving you enough time or doesn't return your phone calls, speak up. If you mistrust your physician's judgment, however, and it happens more than once, you may have to change doctors."

If you don't want to change doctors, and you accept the fact that your doctor may be less than perfect sometimes, then "you have become a sophisticated patient," Marcus adds. "Many people can't cope with the fact that sometimes a physician might disappoint them. A sophisticated patient has to learn that."

And once you accept the fact that your physician is human, it's easier to say, "I don't like the way that situation was handled." If the Doctor Won't Listen

If you have a complaint about a Washington area doctor, and the doctor won't really listen, write:

* District of Columbia Medical Society, Grievance Committee, 2007 I St. NW., Washington, D.C. 20006.

* Alexandria Medical Society, Ethics Committee, 101 S. Whiting St., Alexandria, Va. 22304.

* Arlington County Medical Society, Mediation and Ethics Committee, 4615 Lee Hwy., Arlington, Va. 22207.

* Fairfax County Medical Society, Mediation Committee, 200 Little Falls St., Falls Church, Va. 22046.

* Montgomery County Medical Society, Professional Relations Committee, 15855 Crabbs Branch Way, Rockville, Md. 20855.

* Prince Georges County Medical Society, Professional Relations/Peer Review Committee, Suite 203, 7901 Annapolis Rd., Lanham, Md. 20706.

Or contact your own local or county medical society as listed in the phone book.

Next Week: Some doctors who invite their patients to talk back.