When it comes to medical care, many patients and doctors believe more is better.

But an epidemic of overtreatment — too many scans, too many blood tests, too many procedures — is costing the nation’s health care system at least $210 billion a year, according to the Institute of Medicine, and taking a human toll in pain, emotional suffering, severe complications and even death.

“What people are not realizing is that sometimes the test poses harm,” said Shannon Brownlee, acting director of the health policy program at the New America Foundation and author of “Overtreated: Why Too Much Medicine Is Making Us Sicker and Poorer.”

“Sometimes the test leads you down a path, a therapeutic cascade, where you start to tumble downstream to more and more testing, and more and more invasive testing, and possibly even treatment for things that should be left well enough alone.”

Have you experienced too much medicine? As part of The New York Times’ online series The Agenda, I asked readers to share their stories. More than 1,000 responded, with examples big and small.

Some complained that when they switch doctors they are required to undergo duplicate blood work, scans or other tests that their previous doctor had only recently ordered. Others told of being caught in an unending maze of testing and specialists who seem to forget the patient’s original complaint. I heard from doctors and nurses, too — health professionals frustrated by a system that encourages these excesses.

Terrence Power of Breckenridge, Colo., said that after his wife, Diane, learned she had Wegener’s disease, an uncommon autoimmune disorder, the couple found it difficult to refuse testing recommended by a trusted doctor. The doctor insisted on office visits every three weeks, even when she was feeling well. He frequently ordered blood tests and X-rays, and repeatedly referred her to specialists for even minor complaints. Even when tests came back negative, more were ordered, and she was hospitalized as a precaution when she developed a cold. During one six-month period, she had 25 doctor visits. The couple was spending about $30,000 a year out of pocket for her care.

“He was convincing enough that we felt we needed to have it done,” said Diane Power, 60, who recalls being sedated before an endoscopy procedure, one of the last tests she allowed her doctor to perform. “When they were getting ready to knock me out I was thinking, ‘Why am I doing this?’ But we felt like the doctor knew what to do and we trusted him.”

After several years of physical suffering and near financial ruin from the medical costs, the couple began questioning the treatment after consulting other patients in online support groups. Terrence Power spoke with his own primary care doctor, who advised him to find a new specialist to oversee Diane’s care.

“It’s a really hard thing to determine when they’ve crossed the line,” Terrence said. “You think she’s getting the best care in the world, but after a while you start to wonder, what is the objective? He seemed caring, but he didn’t really consider my wife’s time and the suffering she was going through having all these tests done.”

Under the new doctor’s care, the regular testing stopped and Diane Power was finally able to achieve remission. Now she sees the doctor only four or five times a year.

Sometimes the toll of too much medicine is brief but emotional. Kara Riehman, 43, of Atlanta was vacationing in California when she lost a struggle with an ironing board in her hotel room and ended up with a black eye.

As the bruising peaked around 10 days, she called her doctor to make sure everything looked normal. But instead of seeing her, the doctor, through a conversation with the nurse, ordered a CT scan. She had no symptoms other than a bruised eye, but the doctor never spoke with her or examined her. The scan came back with an ambiguous finding, and the nurse told her it could be a tumor. She was then given an MRI and for two weeks while she waited for the results, she worried she had brain cancer. The nurse called to tell her the MRI was fine.

“It was really terrible,” she said. “It was only two weeks, but there is a lot of cancer in my family. I never actually talked to my doctor through this whole thing.”

The total cost to her insurance company was about $7,000.

“It did change how I think about interacting with the medical system,” Riehman said. “It made me much more of a questioning consumer.”

Jim Donohue, a Brooklyn bank examiner, had to intervene on behalf of his father, now 79, who had a stroke in March 2007. Doctors in Florida put him on several medications, including two antidepressants, and soon after the man began hallucinating and showing signs of dementia. Donohue began researching the drugs and learned they were associated with cognitive problems. He persuaded his father’s doctors to change the medication, and his father quickly improved. He has since recovered and has been living on his own for four years.

“All the medical professionals seeing him along the way, the hospital, two nursing homes and nobody thought of this,” said Donohue, who said his father never should have been given a diagnosis of depression in the first place. “I don’t know if we have too many specialists and every one is trying to practice their specialty, but it should not have happened.”

When Kathryn Gullo, a teacher in the Los Angeles area, gave birth to twins just 25 weeks into the pregnancy, she was thrust into the intense medical care of the neonatal ward that saved her children’s lives. But when her daughter, Grace, was 3 months old she was transferred to a different hospital, where doctors insisted on subjecting her to a battery of tests for symptoms that other doctors had dismissed as normal for her condition.

“We felt like we were being bullied,” Gullo said. “I had enough faith in her previous doctors that it was then easy to say no.”

The family switched hospitals. Their daughter, now 5 and living with mild cerebral palsy and some vision and feeding issues, continues to require specialized care. But recently, when doctors suggested an MRI that would require that their daughter be anesthetized, Gullo and her partner, Katie Ingram, said they asked two key questions: “What new information will this give us?” and “Will it change what we are doing?” After talking to the doctor, they declined the MRI.

“Not every mystery has to be solved, and not every problem has to be addressed,” Gullo said. “That’s hard to get your brain around.”

© 2012 The New York Times Company