Diagnostic Errors
When we visit a doctor, we trust that they will correctly identify what’s wrong and provide appropriate treatment. But when a physician fails to make an accurate or timely diagnosis, the results can be devastating. Diagnostic errors are among the most common and most serious forms of medical malpractice. They can lead to unnecessary suffering, improper treatment, disease progression, or even death.
In California, patients who are harmed by diagnostic mistakes may be entitled to compensation through a medical malpractice claim. To succeed, however, the patient must show that the doctor’s error fell below the standard of care that a reasonably competent physician would have provided under similar circumstances.
Below, we explore the three main types of diagnostic errors—misdiagnosis, delayed diagnosis, and missed diagnosis—and explain how they occur, why they matter, and what legal remedies may be available to victims and their families. If you or a loved one were harmed by a medical mistake at a doctor’s office, clinic or hospital, contact the California trial attorneys at Kalfayan Merjanian, LLP, to speak with an experienced and compassionate California medical malpractice lawyer.
What Is a Diagnostic Error?
A diagnostic error occurs when a healthcare professional fails to correctly and promptly identify a patient’s medical condition. This can happen at any stage of the diagnostic process: during the initial patient evaluation, when interpreting test results, or when deciding which conditions to rule out.
Diagnostic errors are not always due to inexperience or negligence; medicine is complex, and symptoms often overlap. But when a doctor fails to order appropriate tests, ignores critical findings, or misinterprets results that a reasonably careful physician would have recognized, it may constitute malpractice.
Common conditions that are frequently misdiagnosed or missed include:
- Cancer (especially breast, lung, colorectal, and skin cancer)
- Heart attack and stroke
- Pulmonary embolism
- Infections and sepsis
- Meningitis
- Appendicitis
Each of these conditions can worsen rapidly without timely intervention, making an accurate diagnosis absolutely critical.
Misdiagnosis: Treating the Wrong Condition
A misdiagnosis happens when a doctor incorrectly identifies a patient’s illness as something else. For instance, chest pain may be mistaken for acid reflux instead of a heart attack, or a malignant tumor might be diagnosed as a benign cyst.
When a patient is misdiagnosed, they often receive inappropriate or harmful treatments while their actual condition progresses unchecked. Misdiagnosis can lead to:
- Unnecessary medications or surgeries
- Delayed treatment for the real illness
- Permanent injury or loss of function
- Emotional distress and financial strain
In a California malpractice case, a misdiagnosis claim usually requires showing that a competent doctor in the same specialty would have reasonably identified the correct diagnosis based on the patient’s symptoms, test results, and available information.
Delayed Diagnosis: The Right Diagnosis, But Too Late
A delayed diagnosis occurs when a doctor eventually identifies the correct condition, but only after an unreasonable and harmful delay. This often happens when a healthcare provider fails to take a patient’s complaints seriously, doesn’t order diagnostic tests promptly, or fails to follow up on abnormal test results.
For example, if a patient reports symptoms consistent with colon cancer and the doctor delays ordering a colonoscopy for months, the cancer may progress to a more advanced and less treatable stage.
A delay in diagnosis can make the difference between a full recovery and a lifelong disability, or even death. Legally, delayed diagnosis claims are often complex because the plaintiff must prove that an earlier diagnosis would likely have improved the outcome. Expert testimony from medical specialists is usually essential to establish this causal connection.
Missed Diagnosis: Failing to Diagnose at All
A missed diagnosis occurs when a healthcare provider entirely fails to identify a condition that exists. The patient may be told nothing is wrong or may be sent home without further testing. Missed diagnoses are especially dangerous because they often lead to no treatment whatsoever, allowing the underlying condition to advance unchecked.
Missed diagnoses can result from:
- Failure to take a thorough medical history
- Ignoring or discounting patient symptoms
- Inadequate physical examination
- Not ordering appropriate diagnostic tests
- Losing or misinterpreting test results
For example, if a patient goes to the emergency room with symptoms of a stroke and is discharged without proper testing, the missed opportunity for immediate treatment can lead to permanent brain damage.
How Diagnostic Errors Happen
Diagnostic mistakes can occur for many reasons, but they often stem from systemic failures within healthcare settings. Common contributing factors include:
- Communication breakdowns between doctors, nurses, and lab personnel
- Cognitive biases, such as assuming common conditions over rare ones or dismissing patient concerns
- Overreliance on incomplete test results or misread imaging scans
- High patient volume and time pressures, leading to rushed assessments
- Lack of follow-up procedures for abnormal test findings
While human error is inevitable, the law expects physicians and hospitals to implement safeguards like double-checking test results, ensuring clear communication, and properly documenting patient interactions to prevent avoidable harm.
Proving Diagnostic Negligence in California
To bring a successful medical malpractice claim for a diagnostic error, the injured patient must prove:
- A doctor-patient relationship existed.
- The doctor was negligent, meaning they failed to meet the accepted standard of care.
- The negligence caused harm to the patient.
- The patient suffered damages as a result, such as physical injury, medical expenses, or lost income.
California law also requires plaintiffs to file a Notice of Intent to Sue before filing a malpractice lawsuit and to adhere to the statute of limitations, which is generally one year from the discovery of the injury or three years from the date of the malpractice, whichever occurs first. Because these deadlines can vary depending on the circumstances, consulting an experienced attorney as soon as possible is crucial.
Why Legal Representation Matters
Diagnostic error cases are among the most complex medical malpractice claims. They require detailed medical evidence, expert testimony, and a clear explanation of how the outcome would have been different with proper diagnosis. Insurance companies often fight these claims aggressively, arguing that the doctor’s actions were reasonable or that the patient’s condition was already untreatable.
The attorneys at Kalfayan Merjanian, LLP, have extensive experience handling medical negligence cases throughout California, including claims involving misdiagnosis, delayed diagnosis, and missed diagnosis. We understand how to work with medical experts, analyze complex medical records, and build strong cases for victims of preventable medical errors.
Contact Kalfayan Merjanian, LLP
If you or a loved one suffered harm because of a diagnostic error, you deserve answers… and justice. Contact Kalfayan Merjanian, LLP today for a free consultation. Our experienced California medical malpractice lawyers will review your case, explain your rights, and, if retained, help you pursue compensation to recover and move forward.
