My friend's mother lies propped in a hospital bed. She looks amazingly beautiful with her head tilted back and held in place with a black metal "halo" -- amazingly, as I say, because about a week ago she fell down the stairs headfirst, broke her neck, her pelvis, her wrist. Her legs, shoulders and arms are black and blue. Still, she sustained no injuries to her head. She retains her smile and her wit. As the doctor told her, Providence was looking after her. With time and rehabilitation, she will recover.

But the family has a more immediate concern: Will she be safe in the hospital?

The growing concern in health care is that places of healing can also be places of harm. A major key to quality is the nursing staff -- and nurses have been on the critical list for some time. A new report on the nursing shortage from the agency that accredits hospitals puts the danger very simply: "When there are too few nurses, patient safety is threatened and health care quality is diminished."

Indeed. Nearly a quarter of unanticipated complications that led to death or permanent disability in hospital patients stemmed from a shortage of nurses, reported the Joint Commission on Accreditation of Healthcare Organizations this month.

With fewer nurses to care for sicker patients, many hospitals and nursing homes are headed for a meltdown. Some 126,000 nursing positions are now unfilled in hospitals across the country, according to the American Hospital Association. With the aging of 78 million baby boomers, the demand for nurses will grow. But if present trends continue, researchers say, by 2020 there will be 400,000 fewer nurses than needed.

Congress has responded by passing the Nurse Reinvestment Act, signed into law by President Bush on Aug. 1. The legislation provides financial incentives for more women and men to become nurses and get advanced training.

But the real issue is not just recruiting nurses but also keeping them in the ranks. In a study of hospital nurses in Pennsylvania, more than 40 percent reported that they were dissatisfied with their jobs. One in five said they planned to quit within the year.

"The legislation is a good beginning," says Linda Aiken, the study's author and a professor in the school of nursing at the University of Pennsylvania. "It's not enough to solve the problem."

The problem is the hospital environment. For too many nurses, the workload is overwhelming, support staff is inadequate and communication with physicians and hospital administrators is spotty. As Aiken says: "Nurses are concerned that the circumstances don't allow them to practice quality of care."

The result is unnecessary harm to patients. This occurs when, for example, a patient develops an unanticipated complication and the hospital is unable to adequately respond. Nurses call this phenomenon a "failure to rescue." Certainly, the public presumes that a hospital can handle unexpected problems; that's why sick people are there. But, as the commission study shows, hospitals vary in their ability to save patients.

The failure to rescue patients is primarily a failure of the nurse surveillance system. Nurses are the first line of defense in recognizing potentially hazardous conditions and organizing an effective response.

If there aren't enough nurses, problems go undetected. If the relationship between nurses and doctors is poor, problems won't get resolved quickly or easily.

The news that the nursing shortage is a factor in hundreds of deaths and injuries is not a surprise to those on the front lines of hospital care. Nurses complain not only about having too many needy patients to take care of at one time, but also about the club of "mandatory overtime" that can force them to work double shifts.

"I can kill tons if I'm tired," says Barbara Crane, assistant head nurse in the intensive care unit at St. Catherine of Siena Medical Center in Smithtown, N.Y., where nurses went out on strike for more than 100 days last winter to improve their working conditions. "I've worked a lot of overtime. They come to you at 11 and say stay another shift. That means I'm up 25 hours. You want me taking care of your mom? I don't think so."

My friend's mother is in one of the best hospitals in Washington. She was transferred from another facility where she had become seriously dehydrated. The transfer wasn't easy. She had to wait 12 hours for a room. The computerized admitting process thought her first name was a man's, so she was taken to the men's floor before anyone realized the mistake. Not until 3 in the morning was she finally brought to a room.

She is recovering slowly. Her daughter stands by the bed and helps her bend a straw into a can of Ensure. The family has arranged for extra nursing care at their own expense.

It's not easy to be a patient in a hospital these days.