The true meaning of ‘First, do no harm’ for doctors

By Joe Hannan | Fact-checked by Barbara Bekiesz
Published May 31, 2022

Key Takeaways

  • Primum, non nocere is a dictum with muddled historical origins that seems clear on the surface, but becomes distorted on closer inspection.

  • While it’s obvious that explicit attempts to cause harm in medicine are unethical, there is harm—and the potential for greater harm—in any procedure or intervention that violates the body even slightly.

  • Experts say that a more holistic understanding of “First, do no harm” includes identifying foreseeable harm, maintaining high professional standards, and remaining cognizant of knowledge gaps.

First, do no harm. It’s a bedrock principle of medicine so significant that many medical students swear to it. While Primum, non nocere seems simple, upon closer inspection, it’s quite complex.

Scrutiny of the phrase’s history and ethical implications reveals a more nuanced picture of non nocere, one that may be better suited for medicine practiced 2,300 years after the death of its alleged originator.

Muddled origins

“First, do no harm” is attributed to Hippocrates, often called the father of medicine.

Hippocrates did his writing about 430 years before the rise of the Roman Empire. It’s unlikely he would have written Primum, non nocere, a Latin phrase, opting instead to speak and write in his native Greek.

Furthermore, non nocere was not an abstraction from the Hippocratic Oath, as is commonly believed. Instead, the phrase was taken from Of the Epidemics, another of Hippocrates’ works, explained Robert Shmerling, MD, on the Harvard Health Blog.[][] In Of the Epidemics, Hippocrates wrote:

“The physician must be able to tell the antecedents, know the present, and foretell the future—must mediate these things, and have two special objects in view with regard to disease, namely, to do good or to do no harm.”

Granted, there is some overlap with a portion of the Hippocratic Oath, which reads:

“I will follow that system of regimen which, according to my ability and judgment, I consider for the benefit of my patients, and abstain from whatever is deleterious and mischievous.”[]

In both quotes, “there is no clear priority given to the avoidance of harm over the goal of providing help,” Shmerling wrote.

In other words, the “First” portion of “First, do no harm” may be a byproduct of a centuries-long game of telephone.

What else might have been lost in translation?

The nature of harm

Is it even possible to practice medicine without doing some harm? MDLinx posed this question to Lydia Dugdale, MD, director of the Center for Clinical Medical Ethics at Columbia University. She said that anytime a physician uses an intervention that violates the body—even slightly—there are real risks for adverse events.

"Most things doctors do cause ‘harm’ in some way."

Lydia Dugdale, MD

“When we draw blood, we pierce the skin with a needle—that hurts," she continued. "We treat pneumonia with antibiotics that cause unpleasant side effects. We cut out tumors with a scalpel, causing bleeding and opening the body up to the possibility of infection.”

“When we say that the aim of our practice should be to do no harm, what we actually mean is that the benefits of the intervention should significantly outweigh the burdens, and that our interventions should aim at a patient's wholeness or health.”

According to Dugdale, the key distinction is between intending harm (which is clearly unacceptable) and foreseeing harm, which is a common aspect of medical practice. She provided the following example:

You prescribe a new medication for a patient and describe any anticipated side effects. These are the harms you foresee.

“And if the medications seem a reasonable fix, despite potential harms, it's ethical to move forward,” Dugdale said. “But if we know that a medication has the potential to cause grave damage to a patient with no hope for benefit, then to proceed is to intend harm. What can it be otherwise?”

Of course, sometimes medical interventions just don’t work out. A patient develops an unforeseen post-operative infection—or a pharmaceutical leads to an unforeseen adverse event, something outside of the norm.

“These are unfortunate but neither foreseen nor intended, but it's no different, ethically speaking, from any other disaster or accident that befalls us. Bad stuff happens in life,” Dugdale said.

So what, precisely, do we mean when we say non nocere?

Aiming high

Shmerling, writing on the Harvard Health Blog, concluded that applying non nocere is difficult, owing to the unknowable nature of risk and benefit. When assessing both, inside and outside of medicine, we’re making our best guesses based on available data. It’s human nature to over- and underestimate the risks involved.

Shmerling wrote that the path forward is paved with a better understanding of the benefits and risks for tests and treatments.

“Ultimately, it is also a reminder that doctors should neither overestimate their capacity to heal, nor underestimate their capacity to do harm.”

Dugdale expressed a similar sentiment, noting that physicians must continue to “strive for excellence.”

"If our maxim was ‘try not to screw up,’ we’d likely become sloppier."

Lydia Dugdale, MD

She gave an example from parenting. Dugdale tells her children never to lie while acknowledging that there are permissible white lies, like concealing the location of birthday gifts, or the location of siblings during games like hide-and seek.

“But set the bar at white lies, and you end up with children who lie,” Dugdale said. “The same is true for any work we aspire to accomplish. If our standards are low, our quality is low."

"To cultivate excellence in life, maintain the highest standards."

Lydia Dugdale, MD

What this means for you

When applying “First, do no harm,” it helps to maintain this critical distinction: What is foreseeable harm, and what is unforeseeable harm? Clinical training and standards of clinical practice should keep what is foreseeable at the forefront of physicians’ minds.

Related: First, do no harm: Common ethical issues doctors may face

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