Written by: Julie Baqleh
When you visit a doctor, you place your trust in their expertise to accurately identify your condition and provide the right treatment. Unfortunately, medical misdiagnosis happens more often than many people realise, and the consequences can be life-altering. If you suspect that you or a loved one has been misdiagnosed, it’s important to understand your rights and the legal options available to you.
Misdiagnosis can take many forms, from an incorrect diagnosis to a failure to detect a serious condition altogether. In Australia, if such diagnostic errors occur due to medical negligence, you may be entitled to pursue legal action.
Our September 2025 guide explains what constitutes medical misdiagnosis, why these errors happen, and what steps you can take to protect your health, rights, and future. Whether you’re looking for clarity or considering a claim, this guide is designed to support you every step of the way.
What is medical misdiagnosis?
Medical misdiagnosis refers to situations where a healthcare professional fails to correctly identify a patient’s condition. Recognising the different forms it can take is key to understanding when medical negligence may have occurred.
Types of medical misdiagnosis
| Wrong diagnosis | The condition is incorrectly identified, leading to the wrong treatment while the real illness goes untreated. For example, diagnosing anxiety instead of a heart attack. |
| Missed diagnosis | A condition is completely overlooked, even when symptoms or risk factors are present. Missed diagnoses often occur when medical professionals focus solely on the most apparent symptoms, overlooking less obvious signs that may point to a more serious underlying condition. |
| Delayed diagnosis | The correct diagnosis is made, but only after an unreasonable delay. This can happen due to missed tests, poor follow-up, or misread results. |
| Partial diagnosis | One condition is diagnosed correctly, but others are missed, resulting in incomplete treatment. |
Each of these can have serious consequences, and if negligence played a role, you may have grounds for legal action.
Is misdiagnosis medical negligence?
Not always. A misdiagnosis can be medical negligence, but not every misdiagnosis meets the legal threshold.
To prove medical negligence and medical malpractice in Australia, several key elements must be established:
- Duty of care: A doctor-patient relationship existed, meaning the healthcare provider owed you a legal duty.
- Breach of duty: The doctor failed to meet the standard of care expected of a reasonably competent practitioner in similar circumstances.
- Causation: The misdiagnosis directly caused or significantly contributed to your harm.
- Damages: You suffered actual, measurable harm as a result (e.g. worsened condition, additional treatment, pain and suffering, loss of income).
The central legal question is: Would a competent medical professional, faced with the same situation, have made the same mistake? If the answer is no, and harm resulted, then you may have grounds for a medical negligence claim.
Why misdiagnosis happens
Understanding why medical misdiagnosis occurs can help you recognise potential red flags and advocate more effectively for your health. These diagnostic errors can arise from a range of causes, including systemic issues within the healthcare system and individual practitioner mistakes.
Common causes of diagnostic errors
| Cognitive biases | Like anyone, medical professionals can rely on mental shortcuts that lead to errors. Common cognitive biases include:
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| Communication breakdowns | Poor communication between healthcare providers, or between providers and patients, can lead to missed or misinterpreted information crucial for accurate diagnosis. |
| System failures | Inadequate healthcare systems, including:
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| Inadequate follow-up | Failing to monitor patient progress or follow up on abnormal test results can allow conditions to progress undetected. |
| Overconfidence | Some medical professionals may be too confident in their initial assessment and fail to consider alternative diagnoses. |
Legal precedent
In Rosenberg v Percival [2001] HCA 18, the High Court of Australia confirmed that medical professionals must provide care that meets the standard expected of their profession. While following accepted medical practice is important, the Court made it clear that this alone isn’t enough to avoid liability. If a doctor’s actions fall below what a reasonable professional would do—and that causes harm—it may still be considered negligence, even if the actions were common practice.
High-risk scenarios
Certain medical situations are more prone to diagnostic errors:
| Scenario | Common misdiagnosis negligence | Potential consequences |
|---|---|---|
| Emergency Department (ED) | Neglecting to administer time-critical treatments | Fatal heart attacks, strokes |
| Primary care (GP) | Limited consultation time | Untreated diabetes disease |
| Specialist referrals | Treatment delays | Delayed detection leading to advanced-stage cancer |
| Mental health | Stigma, symptom overlap | Missed diagnosis of bipolar disorder leading to inappropriate treatment and hospitalisation |
| Paediatrics | Communication challenges | Failure to diagnose childhood epilepsy, causing seizures and brain damage |
What are common types of misdiagnosis?
Medical misdiagnoses often involve conditions that are commonly misunderstood or have symptoms that resemble other illnesses, such as heart disease, cancer, stroke, infections, and mental health disorders. Recognising these patterns can help you push for a more thorough evaluation when needed.
Frequently misdiagnosed conditions
1. Cardiovascular conditions
Heart attacks and other cardiac events are often misdiagnosed, particularly in women and younger patients. Symptoms may be attributed to anxiety, acid reflux, or other less serious conditions.
2. Cancer diagnosis errors
Cancer misdiagnosis can be devastating, as early detection is often crucial for successful treatment. Common issues include radiologists missing tumours on imaging studies, pathologists misinterpreting biopsy samples, or primary care doctors attributing cancer symptoms to benign conditions.
3. Neurological disorders
Conditions like strokes, seizures, and multiple sclerosis are frequently misdiagnosed due to their varied symptom presentations.
4. Mental health conditions
The overlap between physical and psychological symptoms often leads to misdiagnosis in both directions. Physical conditions are dismissed as mental health issues, or mental health conditions are overlooked entirely.
5. Infectious diseases
Conditions like meningitis, sepsis, and other serious infections may be initially misdiagnosed as less serious illnesses.
Examples of medical misdiagnosis
Real-world examples help illustrate how diagnostic errors can occur and their potential impact:
| Case | Details | Compensation amount |
|---|---|---|
| Stroke misdiagnosis | A man was taken to hospital by ambulance after experiencing symptoms consistent with a stroke, including neck pain, numbness, dizziness, slurred speech, and vision issues. Despite this, emergency staff diagnosed him with heat stroke and discharged him without performing a neurological exam or taking a full medical history. The next morning, while driving his children to the GP, he blacked out and suffered a stroke behind the wheel. He was later admitted to ICU and continues to experience neurological and psychological effects. | $400,000 |
| Tendon injury misdiagnosis | A woman injured her right thumb while using a food processor. Her GP stitched the wound but ignored repeated complaints of severe pain and limited movement over several follow-up visits. The GP failed to investigate for possible tendon or nerve damage. Eventually, hospital tests confirmed a ruptured tendon, requiring surgery and a year-long recovery. She was left with permanent disability in her dominant hand, affecting her daily life and earning capacity. | $300,000 |
| Cancer misdiagnosis and unnecessary chemotherapy | A 61-year-old woman was incorrectly diagnosed with small-cell lung cancer and underwent chemotherapy, only to later discover she actually had carcinoid lung cancer. The unnecessary treatment caused severe brain damage, leaving her unable to communicate or care for herself. Once a high-performing professional, she became fully dependent on her partner for round-the-clock care. Expert medical opinions confirmed the extent of the negligence and lifelong care needs. The case settled at mediation for $3.35 million to support her ongoing care and quality of life. | $3,350,000 |
Timing is crucial in medical misdiagnosis cases. The longer the delay in diagnosis, the more difficult it becomes to prove that earlier intervention would have prevented the harm suffered.
What to do if you think you are a victim of misdiagnosis
If you suspect that you or a loved one has been misdiagnosed, taking immediate action is crucial. Your response can not only improve your health outcomes but also preserve important evidence for potential legal action.
Immediate steps to take
| 1. Advocate for yourself | Don’t hesitate to question your diagnosis or request additional testing if you’re not satisfied with the explanation provided. Trust your instincts about your body and symptoms. |
| 2. Seek a second opinion | Getting an independent medical assessment can reveal diagnostic errors and ensure you receive appropriate treatment. This is particularly important for serious diagnoses or when recommended treatments seem excessive. |
| 3. Document everything | Keep detailed records of:
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| 4. Request your medical records | You have the right to obtain copies of all your medical records. These documents will be crucial evidence if you decide to pursue legal action. |
| 5. Contact a lawyer | If the misdiagnosis has caused significant harm—such as delayed treatment, unnecessary procedures, or financial loss—it’s worth speaking to a medical misdiagnosis lawyer early.
You don’t need to wait until everything is documented. A lawyer can help assess whether what happened might be considered negligence and guide you on next steps. |
When seeking a second opinion, allow the doctor to make an independent assessment based on your symptoms, test results, and examination. To avoid influencing their judgment, consider holding off on mentioning prior diagnoses until they’ve formed their own view, unless urgent medical care is involved.
Building your case
If you believe medical misdiagnosis has occurred, a lawyer can help you identify and gather the right evidence to support your claim.
However, it’s helpful to begin collecting what you can, including:
| Medical evidence |
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| Damage evidence |
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Time limits for medical misdiagnosis claims
Understanding the time limits for pursuing medical misdiagnosis cases is crucial, as missing these deadlines can bar you from seeking compensation regardless of how strong your case might be.
The three-year rule
In Australia, you generally have three years from the “date of discoverability” to commence legal action for medical negligence misdiagnosis. The date of discoverability is when you first became aware (or reasonably should have become aware) that:
- You suffered an injury
- The injury was caused by medical treatment
- The treatment was provided negligently
This isn’t necessarily the date of the misdiagnosis itself, but rather when you discovered the connection between the diagnostic error and your harm.
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Special circumstances
- Children: Time limits for minors typically don’t begin until they reach 18 years of age, giving them until age 21 to commence action.
- Mental incapacity: If you were mentally incapacitated and unable to understand your legal rights, the time limit may be extended.
- Fraud or concealment: If medical professionals deliberately concealed the misdiagnosis or engaged in fraudulent conduct, the limitation period may be extended.
- Extensions: Courts have discretionary power to extend time limits in exceptional circumstances, though this is rarely granted and requires compelling reasons.
Why acting quickly matters
Beyond legal deadlines, there are practical reasons to act promptly:
- Evidence preservation: Medical records, witness memories, and physical evidence deteriorate over time.
- Medical expert availability: Securing expert medical witnesses becomes more difficult as time passes.
- Financial records: Documentation of financial losses becomes harder to compile with the passage of time.
- Continuing damages: Ongoing harm from misdiagnosis may worsen if not addressed quickly.
Why is legal help essential for a medical misdiagnosis claim?
Medical misdiagnosis claims are among the most complex personal injury cases and often involve both legal and medical challenges that go beyond standard personal injury matters.
Proving the principles of negligence (duty of care, causation, and damages) in the context of a misdiagnosis is far more technical. These cases often hinge on complex medical evidence, expert opinions, and an in-depth understanding of healthcare standards and procedures.
An experienced medical negligence lawyer plays a critical role by:
- Interpreting detailed medical records and timelines
- Engaging independent medical experts to support your claim
- Identifying where medical care deviated from acceptable standards
- Demonstrating how that failure directly caused harm.
Without legal support, it’s extremely difficult to gather and present the right evidence, especially when facing well-resourced hospitals or insurers.
When choosing a lawyer, look for a firm that specialises in medical negligence, has a proven track record with misdiagnosis cases, has access to high-quality medical experts, and has clear communication around fees and expectations.
