An estimated 795,000 American patients die or become permanently disabled each year because of medical misdiagnoses, according to a report.

An estimated 371,000 patients die and 424,000 are permanently disabled each year because they are incorrectly diagnosed across a range of medical care settings not just in the family doctor's office, according to the report by the Johns Hopkins Armstrong Institute Center for Diagnostic Excellence.

The estimate "matches data produced from multiple prior studies that focused on diagnostic errors in ambulatory clinics and emergency departments and during inpatient care", the report says.

"Diagnostic errors are, by a wide margin, the most under resourced public health crisis we face," said Dr David Newman-Toker, director of the Johns Hopkins diagnostic excellence center and lead author of the report.

Medical professionals almost always misdiagnose diseases when a person's symptoms look like possible symptoms for a different condition, Newman-Toker told USA Today. The more subtle the symptom appears, the more likely it is the patient's problem will be misdiagnosed, he said.

"We don't miss strokes when somebody is paralyzed on one side and can't talk," he said. "We miss them when they look like something else that's benign."

Heart attacks have such a low rate of misdiagnosis "because we've made a sustained investment over decades" on better diagnostic resources and have passed regulations saying they must be put in place, Newman-Toker said.

For spinal abscesses, their rarity contributes to their high rate of misdiagnoses, he said.

Researchers found strokes that are misdiagnosed are the most serious problem for patients and their families.

Among all cases of stroke, the condition was missed more than 17.5 percent of the time, researchers said.

One of the main reasons is that some people show only dizziness and vertigo as a stroke symptom, which can unfortunately get misdiagnosed as inner ear disease, Newman-Toker said. Or someone who had a stroke could just have headaches.

Doctors aren't currently being trained across the board on how to differentiate dizziness caused by stroke and the same symptom caused by inner ear disease, he said.

Five ailments — stroke, sepsis, pneumonia, blood clots and lung cancer — account for nearly 40 percent of all deaths and permanent disabilities stemming from incorrect diagnoses, according to the report. It found reducing diagnostic errors by 50 percent in the five diseases could cut permanent disabilities and deaths by 150,000 per year.

Because a small number of diseases make up a large share of the problem, researchers say they are hopeful it will be easy for medical care providers to focus their efforts in certain areas.

"It means we can make a lot of headway in a relatively shorter amount of time, without having to boil the ocean," Newman-Toker said.

In December 2022, CNN reported that a study found nearly 6 percent of the estimated 130 million people who go to US emergency rooms every year are misdiagnosed, or about 1 in 18 patients.

The study by the US Department of Health and Human Services' Agency for Healthcare Research and Quality reviewed nearly 300 studies published between January 2000 and September 2021.

The researchers estimate that 7.4 million misdiagnosis errors are made every year; 2.6 million people are harmed in cases that could have been prevented; and 370,000 are permanently disabled or die because of the misdiagnosis. That equates to about 1,400 diagnostic errors every year per emergency room across the country.

Ten of the country's leading emergency physician groups, including the American College of Emergency Physicians and the American Board of Emergency Medicine described the report as "misleading" and "incomplete", CNN reported.

The groups said that they recognize there is always room for improvement but that characterizing the diagnoses as errors is incorrect and a misunderstanding of the aim of emergency medicine, which is to focus on the acute and immediate situation.

The groups issued a letter saying that emergency medicine "is rightfully less concerned with diagnosis and more concerned with appropriate stabilization and referral for future evaluation of a symptom complex.

The role of the emergency physician is ensuring that the patient is started on the appropriate pathway for the ultimate diagnosis and treatment."

The organizations also questioned the studies in the survey, noting that several of them were from emergency departments from other countries.

The letter said, "it is scientifically invalid to extrapolate findings, in particular the calculation of an overall diagnostic error rate, from non-US EDs and compare to the state of emergency care in the US''.