ANCHORING BIAS: When First Impressions Cause Patient Harm

Have you ever gone to the emergency room for abdominal pain?

You mention that you have a history of endometriosis. Within minutes, the focus shifts entirely to your pelvis. You are sent home and told your endometriosis has flared.

Hours later, you return with a ruptured appendix.

This is an example of anchoring bias, and it is very real and very dangerous.

Anchoring bias is not a willful intent to misdiagnose. It is not incompetence. It is a normal way the human brain processes information. But in medicine, that normal mental shortcut can lead to serious errors.

No matter how intelligent or experienced someone is, anchoring bias can affect them — including physicians.

Let’s take a look at how anchoring bias plays out in the non-medical world.

We all have experienced anchoring bias to some degree. We made up our mind about something, and then ignored new information when that didn’t fit into the assumption we had settled on.

Maybe you met someone and thought, “They seem rude.”
Later, even when they were kind, you still felt unsure about them.

Anchoring bias can happen to anyone — including doctors.

Understanding this concept can help patients become more informed participants in their care.

What Is Anchoring Bias?

Anchoring bias is a type of cognitive bias, meaning it is a mental shortcut the brain uses to make decisions quickly.

According to the U.S. Agency for Healthcare Research and Quality (AHRQ), anchoring bias occurs when clinicians rely too heavily on the first piece of information they receive and do not adjust when new information becomes available.

In simple terms:
We “anchor” to our first impression.

Anchoring Bias Outside of Healthcare

Anchoring bias happens in everyday life.

Shopping

Imagine seeing a jacket originally priced at $300, now marked down to $150. Even if you were not planning to spend $150, it suddenly feels like a bargain because your brain is anchored to the original $300 price. This pricing effect is well-documented in behavioral economics research.

Media

The first headline you read about a news story often shapes how you interpret everything that follows. Even if new details emerge, your first impression may remain strong.

Education

Parents sometimes worry about what information a teacher receives before meeting their child. Early labels can shape expectations. That first impression becomes the anchor.

In daily life, anchoring bias may lead to frustration or misunderstanding.

In medicine, it can lead to delayed diagnosis, serious harm, or even death.

Anchoring Bias in Healthcare

Patients are not responsible for diagnosing themselves. That is the clinician’s role.

However, understanding anchoring bias can help you participate more actively in your care.

Doctors work in fast-paced environments. They make hundreds of decisions daily. Early information — symptoms, medical history, lab results, or imaging findings — can quickly form an initial impression.

That first impression can become the anchor.

The Agency for Healthcare Research and Quality (AHRQ) identifies cognitive biases, including anchoring bias, as contributors to diagnostic error.

Diagnostic errors are a significant patient safety concern in healthcare. The National Academies of Sciences, Engineering, and Medicine estimate that medical errors continue to harm an unacceptable number of patients.

Examples of anchoring in medicine may include:

• A symptom might immediately be attributed to a common condition. For instance, an earache in a toddler = an ear infection.
• A test result that the doctor happens upon (an incidental finding) may divert attention from the true diagnosis.
• An early assumption may cloud their judgment, leading them to ignore or dismiss new information that does not fit the original judgment.

Pattern recognition is an important medical skill. It helps doctors diagnose quickly and accurately, which can be life-saving. But when a physician fails to pause and reconsider the original impression, anchoring bias can occur.

Why This Matters for Women

Research shows that women may experience differences in how their symptoms are evaluated.

Both the Centers for Disease Control (CDC) and the World Health Organization (WHO) have documented evidence of both gender and anchor bias experienced by women seeking healthcare.

For example:

• Research has shown that women are more likely to be diagnosed with a mental health condition than men when seeking care for similar pain complaints.
• Additionally, cardiovascular disease is also more likely to be misdiagnosed in women than in men.

The discrepancy persists regardless of the treating physician’s gender.
This is not about blaming individual doctors. It is about understanding how human decision-making operates under pressure.

What Patients Can Do

You are not expected to diagnose yourself.

But you should feel empowered to ask questions.

If you are too ill to speak for yourself, a loved one can ask on your behalf.

Questions you might consider asking:

• “What are the most serious possibilities?”
• “Is there anything dangerous we need to rule out?”
• “Could this finding be unrelated to my main symptoms?”
• “When should I return if symptoms worsen?”

The Centers for Disease Control and Prevention (CDC) and the Joint Commission encourage patients to speak up and ask questions as part of safe healthcare practices.

Healthcare works best as a partnership, and you are a critical member of that team.

Our Shared Goal: Safer Thinking

Anchoring bias is not about accusing healthcare professionals of wrongdoing.

It is about recognizing that all humans—regardless of education or experience—rely on cognitive shortcuts.

In medicine, pausing to reconsider the initial impression can save lives.

Patients and their loved ones should feel empowered to respectfully ask questions. Doing so can encourage thoughtful reflection and careful decision-making.

Learning about anchoring bias helps both patients and physicians move toward safer care.

---

Written by: Dayna Smith, MD | Reviewed: February 18, 2026 | Copyright: myObMD, 2026

---