Failure to diagnose is a type of diagnostic error that occurs when a doctor fails to recognize a patient’s condition. It’s also one of the most common causes of medical malpractice lawsuits. According to the National Academy of Sciences, “most people will experience at least one diagnostic error in their lifetime.” The National Cancer Institute also highlights the importance of identifying near misses and diagnostic errors to improve healthcare quality and patient safety.
A failure to diagnose or a delay in diagnosis affects an estimated 5% of outpatient visits in the United States, or 12 million adults annually, with nearly half of those mistakes causing harm to the patient. Not all patients present with classic symptoms, and diagnostic errors can occur even when presentations are atypical or unusual. A small 2024 study found that certain patient groups, such as those seen for new visits, may experience diagnostic errors at a rate up to 12%.
This article will break down what failure to diagnose means, why it happens, the most commonly affected conditions, and the steps to take if it happens to you, including necessary aspects of the legal process of a misdiagnosis lawsuit. We will also discuss diagnose lawsuits as a broader category of legal actions related to diagnostic errors.
Understanding why and how failure to diagnose happens is key to improving care and reducing risk.
Curious about how to protect yourself? Learn more about your malpractice coverage options here.
Failure to diagnose is often confused with other types of diagnostic errors, but the terms aren’t the same. Here’s the difference:
A healthcare provider’s failure to recognize symptoms can affect recovery and increase the risk of complications for the patient. In many cases, a healthcare provider's failure to diagnose or act promptly can have serious consequences for patient outcomes.
For example, cancer misdiagnosis can occur when early warning signs, such as unexplained weight loss and fatigue, are dismissed as everyday health problems, resulting in delayed treatment. Without prompt treatment, the cancer will likely progress, leading to worse outcomes and financial strain for the patient.
It’s important to understand that not all patient’s missed diagnosis counts as failure to diagnose medical malpractice. A failure to diagnose may be considered medical malpractice in the form of doctor’s negligence if it falls below the accepted standard of care and causes harm. In legal terms, a doctor's failure to properly diagnose a condition, especially when it results in injury or worsened health, can be central to a malpractice claim. The legal threshold for malpractice is met when medical negligence—meaning the healthcare provider did not act as a reasonably competent provider would under similar circumstances—can be proven.
Accurately identifying a patient's medical condition is crucial to prevent harm and avoid the consequences of diagnostic errors.
Let’s look at when a failure to diagnose actually becomes a legal issue.
In medical malpractice lawsuits concerning failure to diagnose a medical condition, generally speaking, failure to diagnose malpractice must be proven by showing a doctor didn’t meet the standard of care and thus the patient suffered harm.
A person usually needs to show four things to make a successful claim:
It is important to act quickly after a failed diagnosis, as there are strict legal deadlines (statute of limitations) for filing a claim.
In some cases, a patient can pursue damages under the lost chance doctrine even if an earlier diagnosis wouldn’t have guaranteed a better outcome. Instead, in these medical malpractice cases, the plaintiff must prove that as a result of the misdiagnosis, they lost the chance of a better outcome.
These types of cases can be more difficult for defendants because a “lost chance” of a better outcome is easier to establish than the misdiagnosis “more probably than not” caused a worse outcome. Patients have the right to pursue compensation for harm suffered as a result of a failure to diagnose.
In the United States, malpractice law is mostly handled by the states rather than at the federal level. Doctors are generally required to carry malpractice insurance to cover the risks of lawsuits. While some cases might go to trial, most will be dismissed before trial or otherwise reach a failure-to-diagnose lawsuit settlement out of court. Misdiagnosis lawsuits are also commonly resolved through settlements rather than trials.
Medical malpractice laws, including failure to diagnose, can vary dramatically from state to state.
Key differences include:
All states require an expert medical witness to educate the court and jury on what a qualified doctor would have done under the same or similar circumstances.
Economic damages from negligence can include additional medical expenses, lost wages, and costs for adaptive equipment.With a few exceptions, these kinds of damages are not subject to caps. On the other hand, non-economic damages cover losses like physical pain and emotional distress.
In some states, for example, California, Colorado, Utah & Texas have caps that operate to limit non-economic damages, typically as a result of legislated tort reform measures that have been upheld in the Courts. Other states, for example, New York, New Jersey, Illinois & Pennsylvania do not have limits, either because there has been no tort reform measure or because such measures have been determined unconstitutional by the Courts.
How long does a patient have to sue for misdiagnosis? The medical malpractice statute of limitations is a legal deadline for filing a medmal lawsuit. It used to be more common that the statute of limitations started to run on the date of the negligent act or omission, for example the date of the misdiagnosis.
However most states now adopt the “discovery” rule, which means the statute begins to run from the time the patient knew or reasonably should have known that they were injured, and that the injury may have been caused by medical negligence. Depending on the state, the statute of limitations can be anywhere from one year to six years, although it’s most commonly two or three years.
Finally, diagnose settlements can result in significant compensation for patients harmed by diagnostic errors. It’s best to check your state’s rules or speak with a local attorney if you think you may have a claim.
Medical teams can still make mistakes even with advanced science and years of experience. Typically, these reasons fall under the following three categories:
Understanding these reasons might help explain how certain conditions can be overlooked. The next section will review the conditions that are most likely to result in a diagnostic error.
Diagnostic errors are fairly common. A 2024 study published in BMJ Quality & Safety estimates that approximately 795,000 Americans experience serious harm each year because of diagnostic errors, including 371,000 deaths and 424,000 permanent disabilities. Timely and accurate diagnosis of medical conditions is crucial to prevent harm and ensure patients receive the care they need.
Generally, being diagnosed early or in a timely manner can help slow disease progression and improve outcomes. It can also mitigate the financial burden and prevent the need for more serious and invasive treatments. Certain conditions, however, are more likely to be overlooked than others. Diagnostic errors, including wrong diagnosis, can occur in various healthcare environments, including hospitals, outpatient clinics, and long-term-care facilities such as rehabilitation centers, and may lead to serious health outcomes and legal claims, including medical malpractice claims.
According to research from the Johns Hopkins Armstrong Institute, three-quarters of serious harms from diagnostic errors fall under the “big three” categories: cancers (37%), vascular (blood flow-related) events (22%), and infections (13%).
Once a correct diagnosis is made, providing appropriate treatment without delay is essential. Prompt treatment following a timely diagnosis can prevent complications and improve recovery, especially when conditions are life threatening.
Early signs of lung cancer, like a persistent cough or trouble breathing, might often be mistaken for bronchitis, pneumonia, or other common respiratory infections. About 6–7% of lung cancer cases are initially misdiagnosed in primary care settings. A delayed lung cancer diagnosis leads to delays in treatment that make lung cancer the deadliest cancer in the United States.
Other commonly mistaken cancers include:
Research from a 2019 study suggests that missed cancer diagnoses represented 46% of the cases of primary care diagnostic errors, the majority of which involved errors in clinical judgment. Examples include failure to order or a delay in ordering a diagnostic test, or an appropriate referral consultation.
Stroke, a vascular event, is one of the leading causes of disability and death. Early warning signs like dizziness, headache, or trouble speaking can be mistaken for less serious issues, especially in younger people. Studies suggest that about 9% of strokes are initially misdiagnosed. Failure to diagnose a stroke can lead to permanent disability or death due to brain damage, and there have been cases where doctors failed to recognize these symptoms in time, resulting in serious consequences.
Other commonly mistaken vascular events include:
Pulmonary embolism can also be caused by fat or air bubbles, not just blood clots, and these can obstruct pulmonary arteries and result in life-threatening complications.
Sepsis is a serious immune response to an infection. Early symptoms such as fever, shortness of breath, or disorientation can be confused with a mild condition, making diagnostic errors common. Blood tests are a crucial tool that can help doctors quickly identify serious infections like sepsis, allowing for early detection and intervention to prevent complications. If left untreated, sepsis can progress to septic shock, which causes a dangerous drop in blood pressure and can result in organ failure and death.
Sepsis accounts for over 250,000 deaths annually in the United States, and a lawsuit concerning failure to diagnose sepsis may arise if symptoms are missed, which research suggests happens in 8 to 20% of cases.
Other commonly mistaken infections include:
Missing or delaying the diagnosis of heart attacks can have fatal consequences. Prompt recognition and treatment are critical to prevent serious harm or death. If a heart attack is misdiagnosed or not treated quickly, it can lead to severe complications and may result in legal claims or malpractice cases against healthcare providers.
Reducing diagnostic error is a shared responsibility among medical professionals and patients. Medical professionals can help lower the risk of diagnostic error by reviewing all medical records, ordering appropriate tests, and considering a wide range of possible diagnoses. Effective communication between providers is also essential to ensure that important information is not missed or misunderstood.
Doctors rely on a patient's transparency. Patients can contribute by providing a complete and accurate medical history, tracking their symptoms and treatment side effects. Working collaboratively is vital, as is seeking a second or referring for consultation with a specialist if something doesn’t feel right.
By working together, everyone involved in the healthcare process can help minimize diagnostic errors and improve health outcomes for all patients.
Is delayed diagnosis medical negligence? Not always. A delayed diagnosis may be negligence when medical professionals fail to follow standard procedures and the delay leads to harm, such as worsened symptoms, limited treatment options, or additional medical costs.
Even the most careful and experienced doctors can experience failure-to-diagnose medical malpractice claims. Every medical provider, not just doctors, should consider malpractice insurance to protect against such claims. Having reliable medical malpractice insurance can help put you at ease with protection from the financial strain, legal risk, and emotional stress of defending your case.
Indigo offers comprehensive malpractice insurance with AI-powered underwriting for a personalized fit to your needs and budget.
Get in touch today to safeguard your practice against rising risks with the right medical malpractice insurance coverage.
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