When medical advice changes

The most difficult words a doctor may have to say are not always, “You have a serious illness.” Sometimes they are, “We now know something we did not know before, and I think we should change your treatment.”

For patients, this can be unsettling. Was the old advice wrong? Was the medication they faithfully took for years unnecessary? Did it cause harm? And if doctors change their minds today, why should anyone believe what they say tomorrow?

For physicians, the discomfort is just as real. We spend years studying, training, and developing ways of practicing that eventually become second nature. We prescribe treatments that have served our patients well, often following recommendations we learned from respected teachers and established guidelines. Changing these practices can be difficult, particularly when we have been doing things a certain way for decades. Yet remaining faithful to an old recommendation simply because it is familiar does not make it right.

Menopausal hormone therapy is one example of how medical advice can change, sometimes dramatically. For years, hormones were widely prescribed, with the expectation that they might provide long-term health benefits. Then, in 2002, findings from the Women’s Health Initiative raised concerns about breast cancer and cardiovascular risks associated with a particular estrogen-progestin regimen. Prescriptions declined sharply, and many women became afraid of taking hormones altogether.

Over the years, further analyses provided a more nuanced understanding of the risks and benefits. We have learned that a woman’s age, the timing of treatment, the type of hormones used, and her individual health risks all matter. In 2025, the US Food and Drug Administration initiated changes to hormone therapy warnings, approving revised labeling for several products in 2026.

Important risks remain, but menopausal hormone therapy is now recognized as an effective treatment for appropriate women with bothersome symptoms and for preventing bone loss. Unfortunately, the fear created more than two decades ago persists, leaving some physicians hesitant to prescribe hormones and many women reluctant to consider them.

Nutrition advice has undergone similar changes. Remember when eggs were considered unhealthy because of their cholesterol content? We now understand that overall dietary patterns, including saturated fat and fiber intake, matter more than focusing on a single food. This does not mean we should eat eggs without limits, but rather that nutritional recommendations have become more balanced.

Screening guidelines also evolve. In 2024, the US Preventive Services Task Force recommended mammography every two years beginning at age 40 for women at average risk, changing its earlier advice that women in their forties make individual decisions about when to begin. Different medical organizations may still recommend different screening intervals, reflecting how evidence can be interpreted in the context of benefits, risks, and patient preferences.

Even familiar medications are reassessed. Low-dose aspirin was once commonly recommended to prevent a first heart attack. We now know that in many older adults without established cardiovascular disease, the increased risk of bleeding may outweigh the benefit. However, aspirin remains important for many patients who have already experienced a heart attack or stroke.

These changes do not necessarily mean that doctors were careless or that everything previously taught was wrong. Medical knowledge is built gradually, with each new study adding to or sometimes challenging what came before. What seemed reasonable based on the available evidence years ago may no longer be the best approach today.

The greater challenge is learning to accept that change. As physicians, we are expected to keep learning throughout our careers, but unlearning can be considerably harder. It requires us to question familiar practices, acknowledge uncertainty, and sometimes admit that something we once recommended may no longer be beneficial. There may even be situations when a treatment previously considered safe is found to cause harm. In these instances, patients deserve an honest explanation rather than a defensive justification.

This is where communication becomes particularly important. Patients who have trusted their doctors for years may feel confused, disappointed, or even betrayed when recommendations change. Physicians cannot simply tell them that guidelines are different now and expect them to understand. We need to explain what has changed, why it matters, and how the new information applies to their particular circumstances.

Patients, in turn, should feel comfortable asking questions rather than abruptly stopping medications or changing treatments because of something they read online. A new study or a sensational headline does not automatically mean that established treatments should be abandoned. Guidelines provide direction, but good medical care still requires individual judgment.

In medicine, we rarely deal in absolutes. While diseases may follow recognizable patterns and treatments are guided by scientific evidence, every patient is different. What works for one person may not be appropriate for another, and what was considered best practice yesterday may be improved upon tomorrow.

As a physician, I hope never to become so comfortable with what I know that I stop questioning it. Our responsibility is not to defend every decision we have ever made, but to make the best decisions possible with the knowledge available to us, while remaining open to what we have yet to learn.

Changing one’s mind in the face of better evidence is not a sign of weakness or inconsistency. It reflects the humility to recognize that we do not know everything, the courage to change when necessary, and an enduring commitment to doing what is best for our patients.