Diagnostic Errors and the Standard of Care: How Negligence Is Proven

Another doctor diagnosed something your previous doctor didn’t catch. Was your first doctor’s mistake?

Just because someone misdiagnosed you does not automatically mean you suffered medical malpractice. To prove you suffered medical malpractice, you need to show that your care was lacking and what that did to your body.

Table of contents

• When Did a Mistake Occur?
• What is Considered the Standard of Care?
• Elements of Medical Malpractice
• Timeline Of Events
• What Do Medical Experts Look At?
• Determining If Your Diagnosis Was Late Enough To Harm You
• If You Think Your Diagnosis Was Missed, What Can You Do?
• Collecting Information

When Did a Mistake Occur?

You may not get the correct diagnosis; it can take time, or the wrong diagnosis could be given. Mistakes can happen while examining you, reading your test results, or even telling you those results.

A 2025 study in BMJ Quality & Safety estimated that 7.2% of admissions to a general medicine service at one US hospital involved harmful diagnostic errors. It was not a national malpractice rate.

Having a diagnosis come later does not always mean your original doctor was negligent. There are many factors that go into why someone is not diagnosed earlier. Your initial symptoms may be vague, your results could be inconclusive, and your first doctor may have thought of a different diagnosis.

Sometimes the diagnosis is correct, but the doctor may not have done everything necessary after learning the results. Ordering more tests, sending you to see another specialist, or even informing you to come back if certain symptoms appear.

What is Considered the Standard of Care?

The standard of care is the skill, knowledge, and care that a reasonably careful professional in the same field would use in similar circumstances. The question is what reasonable care is required, not whether the doctor did everything possible.

There are different types of providers, so what one person should know will not apply to everyone. There are certain things an ER doctor should know if a patient comes in with sudden symptoms, but a specialist who reads your X-ray may not.

Will there be more tests, immediate treatment, referrals, or more information that you should know before you leave? 

Depending on your case, it may be wise to test you right away, or you may need to schedule a follow-up appointment to ensure that you’re okay.

verdictvictory.com/medical-malpractice explains more about how malpractice is determined and if you suffered harm due to lack of care from your provider.

While these guidelines can give you information, keep in mind that there are different ways to handle a patient with the same symptoms.

Elements of Medical Malpractice

A medical malpractice claim generally requires proof of four connected elements to succeed: duty, breach, causation, and damages. Filing requirements differ by state.

Your Provider Owe You a Duty Of Care

Once your provider accepts you as their patient, they owe you a duty of care. Visit and treatment records may help establish which providers owed a duty of care. Whether any of them breached that duty and caused harm needs separate proof.

It may also be possible that your doctor, the facility, and the hospital can share responsibility. You will need to figure out who failed you.

Your Provider Breached Their Duty Of Care

A breach means a specific action or failure to act fell below the applicable standard of care. Records and, in most medical-negligence cases, qualified expert evidence help show what a reasonably careful provider would have done differently.

Your Injury Was Caused By The Provider’s Action

Did the provider’s action or failure to act cause or worsen an injury? The condition itself may cause harm, so a claim needs evidence showing what additional harm the breach probably caused.

You Have Damages Due To The Provider’s Carelessness

Make sure you collect information on how this affected you financially, or if you were injured in any way.

Timeline Of Events

As mentioned above, you want to find out when your symptoms started, when you were tested, and what information you were given. Your timeline should begin with when you experienced your first symptoms, and not when you were finally diagnosed.

Information you should collect includes, but is not limited to:

• Notes from your visits, tests, and results
• When you were referred to a specialist, or sent home to schedule another appointment
• Any information your doctor gave you, and any communication through patient portals
• Information on your final diagnosis and any treatments you’ve undergone since

Try to map out your timeline with these pieces of information, and see if there is any information missing.

Maybe your X-ray showed something, but no one told you to come back, or informed your other doctor that they need to look at your X-ray. Just because the information is in your file does not mean it was helpful to you.

A timeline of events can also help you. If you see multiple doctors, you may notice that they did not follow through with your medications or inform your next doctor about what they were doing to help your condition.

What Do Medical Experts Look At?

A qualified medical expert may assess the applicable standard, whether care fell below it, and whether an earlier diagnosis probably would have changed the outcome. Some questions may remain uncertain.

They will analyze your symptoms, other diseases that could have been causing them, and if your provider should have performed any tests or started treatment sooner.

There will be research that backs up the standards they use, but some experts may differ. Make sure your expert knows what they are talking about when analyzing your case.

Determining If Your Diagnosis Was Late Enough To Harm You

As stated above, your medical expert will help determine if your provider should have caught your disease earlier.

If your infection was not caught, and now you need more treatment, could they have caught it sooner? If they caught your infection, would you still have ended up needing that treatment?

Cancer may be diagnosed after too; if they could have performed more tests, would your cancer have been less advanced? If a fracture was initially missed, did delayed treatment cause further damage or a longer recovery?

All these questions can be answered by your medical expert; they can even show you what could have happened if your provider took the correct action.

If You Think Your Diagnosis Was Missed, What Can You Do?

If you are still experiencing symptoms, keep seeking medical attention.

Start collecting information from your visits, tests, and any communication with your doctors. Collect all your bills and how much you’ve missed from work. Make sure to understand your diagnosis and what your treatment will be going forward.

If you don’t understand your visit, ask for your lab results and X-rays; they can give you more information than your doctor’s visit may.

Keep all of your information, and create a personal timeline of events.

Once you feel confident that your doctor made a mistake, speak with a malpractice lawyer. They can analyze your case and let you know if you have time to file; some states have time restrictions on these cases.

Collecting Information

A missed diagnosis raises questions, but does not establish malpractice. Records and expert review can help determine whether care fell below the standard and caused harm.