How Failure To Diagnose Can Affect A Medical Malpractice Case

Maybe you kept going back. The cough was probably allergies. The chest tightness was stress. The lump was something to watch. Then a scan or an emergency room visit finally gave it a name, and after the shock came a harder thought: should someone have caught this sooner?

You are far from alone in asking. A national estimate of serious harm from diagnostic error, led by Johns Hopkins researchers, found that roughly 795,000 Americans die or are permanently disabled after a diagnostic error each year. An earlier review of 25 years of paid malpractice claims found diagnostic errors were the most common type of claim and made up about 35 percent of all payments.

Still, a missed diagnosis is not automatically malpractice. Early signs of serious and harmless conditions often look alike. A claim generally has to show that care fell below the accepted standard and that this shortfall caused real, added harm.

What Does Failure To Diagnose Mean?

The National Academies of Sciences, Engineering, and Medicine describe diagnostic error as a failure to reach an accurate and timely explanation of a patient’s health problem, or a failure to tell the patient that explanation. The second half matters, because a correct answer sitting unread in a chart can do as much harm as a wrong one. The National Academies report on improving diagnosis concluded that most people will experience at least one diagnostic error in their lives.

These cases tend to follow a few patterns:

• Missed diagnosis. The condition was never identified, even though the signs were there.
• Delayed diagnosis. The right answer came later than a careful provider would likely have reached it.
• Wrong diagnosis. The patient was treated for one problem while the real one progressed.
• Testing and follow-up failures. A needed test was never ordered, a result was misread, or an abnormal finding was never passed on.

Working out which pattern fits, and whether it amounts to negligence, takes a close read of the records. A medical malpractice lawyer in Chicago, IL can review that material and consult medical experts to see whether a diagnostic error may support a claim. The trial lawyers at Goldberg & Goldberg represent patients in these matters and look closely at the treatment decisions made before an injury.

The key issue is rarely just whether the first diagnosis was wrong. It is whether a reasonably careful clinician, with the same information, would have acted differently.

Standard Of Care Is Central To The Case

The standard of care is not perfection. It is what a reasonably careful provider in the same field would have done in similar circumstances, so an emergency physician is measured against other emergency physicians.

Part of that standard is the differential diagnosis, the working list of conditions that could explain a patient’s symptoms. Good practice means keeping dangerous possibilities on that list until they are reasonably ruled out.

Top-rated medical malpractice attorneys often test each step of care against that standard, looking at the history taken, the physical exam, lab work, imaging, referrals, follow-up instructions, and whether the provider recorded their reasoning. A claim usually has to answer four questions:

Hindsight is a trap. Once a diagnosis is known, every clue can look obvious, so a fair review judges the provider by what they knew, or reasonably should have known, at the time. A poor outcome alone does not prove the standard was breached.

Diagnostic Errors Can Happen In Different Ways

Most diagnostic errors come from a chain of smaller breakdowns rather than one dismissive moment. A study of closed malpractice claims from outpatient care reviewed 181 cases where a missed or delayed diagnosis harmed a patient. Cancer was involved in 59 percent, and most cases had more than one failure point.

The figures add up to more than 100 percent because most cases involved several breakdowns.

Communication gaps are a risk of their own. A review of more than 5,400 primary care patient records found that clinicians failed to tell patients about a clinically significant abnormal result, or failed to document telling them, about 7 percent of the time. Some practices almost never missed one, while others missed about one in four. The best performers told patients about every result and asked them to call if they had not heard back by a set time.

You can use that today. When you have a test, ask when the result should be ready and who will contact you if it is abnormal. If the date passes and no one calls, call them. Silence is not the same as a normal result.

A Delayed Diagnosis Must Cause Additional Harm

This is where many cases succeed or fail, and it can be hard for families to hear. Even when a diagnosis clearly came too late, the law asks what difference the delay made.

Picture two patients whose cancers were both found eight months late. In the first, the disease had already spread at the missed visit, and the outcome would likely have been much the same. In the second, the tumor was small when it should have been found but had reached nearby lymph nodes by the time it was—only the second shows clear added harm from the delay.

States also differ when a patient’s chances were already limited. Some allow a claim for a meaningful lost chance of recovery, while others require proof that a better result was more likely than not.

Earlier Treatment May Have Changed The Outcome

In other cases, timing clearly matters. Medical experts often lay out two timelines: what actually happened, and what most likely would have happened with a timely diagnosis. The second might show that the patient could have:

• Had a smaller operation, or avoided surgery entirely.
• Skipped chemotherapy or radiation that later became necessary.
• Kept an organ, a limb, or abilities such as speech or walking.
• Avoided a complication such as sepsis or a ruptured appendix.

The closer this comparison stays to the patient’s own records and solid medical evidence, the stronger it tends to be.

Cancer Cases Can Raise Complex Diagnostic Questions

Cancer appears often in delayed diagnosis claims because stage at diagnosis shapes treatment options and outlook. The National Cancer Institute’s overview of how cancer staging works explains how doctors describe tumor size and spread, and how they use that to plan care. The gap between the stage a cancer could have been caught at, and the stage it was found at is often the core of the case.

Reviewers often look at moments such as an imaging report recommending follow-up that no one scheduled, rectal bleeding put down to hemorrhoids without the bowel check a patient’s age and symptoms called for, or unexplained weight loss that led nowhere. None of these is automatically negligent, but each is the kind of decision experts examine.

Every cancer behaves differently. Some grow slowly over years, others move fast, so each case depends on the specific cancer, its progression, the patient’s history, and the exact diagnostic chances that were allegedly missed.

Heart Attacks And Strokes May Require Prompt Recognition

The Johns Hopkins estimate found stroke was the single largest source of serious harm from misdiagnosis, missed in about 17.5 percent of cases, compared with about 1.5 percent for heart attacks. Stroke can show up as dizziness, imbalance, or headache, symptoms shared with far more common problems.

Heart attacks can be subtle too. The American Heart Association’s guide to heart attack symptoms in women notes that women often blame warning signs on acid reflux, the flu, or normal aging, and are somewhat more likely than men to have shortness of breath, nausea, and back or jaw pain.

If you have any of these symptoms right now, stop reading and get help. The CDC’s list of warning signs of stroke advises calling 911 at once, noting when symptoms started, and not driving yourself to the hospital. The most effective stroke treatments work only within a limited window.

In a malpractice review, investigators look at when symptoms began, what was reported at triage, how quickly tests such as an ECG or brain imaging were done, and whether specialists were called. The legal question is whether the team responded reasonably to what they knew or should have known at the time.

Medical Records Help Establish The Timeline

A clear timeline is often the backbone of these cases. Records show when a symptom was first reported, which tests were ordered, and how results were handled.

You have a federal right to access your own health records under HIPAA. In general, a provider must act on your request within 30 calendar days, may extend that once by up to 30 more days with a written reason, and can charge only a reasonable, cost-based fee. Records worth requesting include:

• Office notes from primary care and every specialist, including telehealth visits.
• Emergency department records, especially triage notes, which capture what you said on arrival.
• Imaging reports and the actual images, since an expert may want to see the scan itself.
• Lab results, portal messages, referral orders, and appointment histories, including cancellations.

Alongside official records, write your own account while memory is fresh. Calendar entries, texts to family, and work absence records can confirm when symptoms began and how often you raised them. Keep originals exactly as they are.

Medical Experts Often Play An Important Role

These cases usually rely on qualified medical experts to explain what should have happened and whether the gap mattered. In Illinois, a malpractice complaint generally must include an affidavit confirming the case was reviewed with a qualified health professional who found a reasonable and meritorious basis for it.

The right expert depends on the question. A radiologist may address whether a finding on a scan was missed, and a pathologist how a biopsy was read. An oncologist can explain how a cancer likely progressed, while an emergency physician, cardiologist, or neurologist may weigh in on chest pain or stroke care.

Good experts also filter out weak claims by separating a negligent error from a reasonable judgment call that turned out to be wrong.

Patient Conduct May Become Part Of The Investigation

The defense may look at whether the patient followed advice, kept appointments, completed ordered tests, and described symptoms accurately. If a doctor documented an urgent referral and the patient never went, that can change the analysis. Many states reduce or bar compensation based on a patient’s share of responsibility.

The details matter, though. Was the urgency made clear, or was it a vague suggestion to follow up sometime? Was the referral actually sent? On the other side, records of repeated visits for the same complaint without a proper workup can strengthen questions about the provider’s response.

Be fully honest with your lawyer from the start, including the appointment you wish you had kept. It is far better for your own team to hear it first.

Damages Can Extend Beyond Additional Medical Bills

Compensation in a delayed diagnosis case is generally tied to the extra harm caused by the delay, not the illness itself. Someone who would have needed treatment anyway may not recover from that treatment, but may recover from harsher treatment, complications, or shortened life expectancy the delay caused.

Depending on state law, damages may include:

• Added medical costs, such as surgery, rehabilitation, medication, and ongoing care the delay made necessary.
• Lost income and reduced earning capacity when a worsened condition affects work.
• Future care needs, which can be the largest part of a claim when harm is permanent.
• Nonfinancial losses, such as physical pain, disability, and loss of normal daily life.

Wrongful Death Claims May Follow A Missed Diagnosis

Losing someone and then wondering whether it could have been prevented is a heavy kind of grief. Wanting answers is natural, and so is needing time first.

When a diagnostic failure may have contributed to a death, surviving family members or the legally authorized representative may investigate whether earlier treatment could have changed the outcome. Wrongful death and survival laws differ among states and decide who may bring a claim and which damages are available.

One point is time-sensitive. If the cause of death is unclear, families can ask about an autopsy, which generally needs to happen soon after death and can settle questions records cannot. Expert testimony must then connect the earlier mistake to the death under the legal standard that applies.

Filing Deadlines Can Affect A Malpractice Claim

Malpractice claims are subject to strict deadlines, and failure to diagnose cases make timing tricky because patients often learn about an earlier error much later.

Illinois shows how these rules can stack. Under 735 ILCS 5/13-212, a claim generally must be filed within two years of when the patient knew, or reasonably should have known, of the injury and its possible link to negligent care. There is also an outer limit of four years from the act or omission itself, which can apply even if the patient had no idea anything was wrong. Different rules apply to minors, and certain exceptions exist.

Other states use different periods and starting points. Talking with a lawyer early does not commit you to a lawsuit, but it protects your options while you decide.

Evaluating The Full Effect Of A Missed Diagnosis

A failure to diagnose can shape a malpractice case in several ways. Lawyers and experts must work out what the provider should reasonably have done, when the correct diagnosis should have been made, and whether earlier treatment would likely have changed the outcome. Sometimes the answer is that an error happened without causing added harm, which weighs heavily on whether a viable claim exists.

Through all of it, your health comes first. Keep attending appointments and following your current treatment plan, since stopping care can hurt your health and weaken a claim. Ask for a second opinion if you have doubts, and ask your doctor directly what else could explain your symptoms and what changes should bring you back sooner.

When a missed or delayed diagnosis lets a condition progress or forces more extensive treatment, the consequences can be substantial. A careful legal and medical review can show whether the diagnostic process fell below the standard of care, and whether that failure caused losses for which compensation may be available.

Disclaimer

References

• Newman-Toker DE, Nassery N, Schaffer AC, Yu-Moe CW, Clemens GD, Wang Z, Zhu Y, Saber Tehrani AS, Fanai M, Hassoon A, Siegal D. Burden of serious harms from diagnostic error in the USA. BMJ Quality & Safety. 2024;33(2):109-120. doi:10.1136/bmjqs-2021-014130
• Saber Tehrani AS, Lee H, Mathews SC, Shore A, Makary MA, Pronovost PJ, Newman-Toker DE. 25-Year summary of US malpractice claims for diagnostic errors 1986-2010: an analysis from the National Practitioner Data Bank. BMJ Quality & Safety. 2013;22(8):672-680. doi:10.1136/bmjqs-2012-001550
• National Academies of Sciences, Engineering, and Medicine. Improving Diagnosis in Health Care. Balogh EP, Miller BT, Ball JR, editors. Washington, DC: The National Academies Press; 2015. doi:10.17226/21794
• Gandhi TK, Kachalia A, Thomas EJ, Puopolo AL, Yoon C, Brennan TA, Studdert DM. Missed and delayed diagnoses in the ambulatory setting: a study of closed malpractice claims. Annals of Internal Medicine. 2006;145(7):488-496. doi:10.7326/0003-4819-145-7-200610030-00006
• Casalino LP, Dunham D, Chin MH, Bielang R, Kistner EO, Karrison TG, Ong MK, Sarkar U, McLaughlin MA, Meltzer DO. Frequency of failure to inform patients of clinically significant outpatient test results. Archives of Internal Medicine. 2009;169(12):1123-1129. doi:10.1001/archinternmed.2009.130
• Hanna TP, King WD, Thibodeau S, Jalink M, Paulin GA, Harvey-Jones E, O’Sullivan DE, Booth CM, Sullivan R, Aggarwal A. Mortality due to cancer treatment delay: systematic review and meta-analysis. BMJ. 2020;371:m4087. doi:10.1136/bmj.m4087
• National Cancer Institute. Cancer Staging. National Institutes of Health. https://www.cancer.gov/about-cancer/diagnosis-staging/staging
• American Heart Association. Heart Attack Symptoms in Women. https://www.heart.org/en/health-topics/heart-attack/warning-signs-of-a-heart-attack/heart-attack-symptoms-in-women
• Centers for Disease Control and Prevention. Signs and Symptoms of Stroke. https://www.cdc.gov/stroke/signs-symptoms/index.html
• US Department of Health and Human Services, Office for Civil Rights. Individuals’ Right under HIPAA to Access their Health Information. https://www.hhs.gov/hipaa/for-professionals/privacy/guidance/access/index.html
• Illinois Compiled Statutes. 735 ILCS 5/13-212 and 735 ILCS 5/2-622.