People searching for medical negligence cases are often trying to answer the same question: does my situation match a pattern courts have recognised as negligence? The answer always depends on the specific facts, but recurring categories of medical cases do exist, with well-established legal tests and documented outcomes. This guide covers the most common types, the landmark cases that defined the law, and what they mean in practice for anyone considering a claim.

Nothing here is legal advice. For advice specific to your circumstances, contact a solicitor regulated by the Solicitors Regulation Authority.

What makes medical cases count as negligence?

A medical case amounts to negligence when three elements are all proved: a duty of care existed between the clinician and the patient, that duty was breached, and the breach caused the harm suffered. All three must be established. Proving two of the three is not enough.

The legal benchmark for breach is the Bolam test, from Bolam v Friern Hospital Management Committee [1957] 1 WLR 582. A clinician is not negligent if they acted in accordance with a practice accepted as proper by a responsible body of medical opinion in the relevant specialty. A poor outcome, without more, does not establish a breach. The question is always whether the care fell below the standard a competent practitioner in that field would have provided, not whether the outcome was worse than hoped.

Causation is often the harder limb. The "but for" test from Barnett v Chelsea and Kensington Hospital [1969] 1 QB 428 requires the claimant to show that, but for the negligent act, the harm would not have occurred. In delayed diagnosis cases, this means showing that earlier intervention would have produced a materially better outcome, which almost always requires detailed independent expert evidence on the clinical picture at the point when action should have been taken.

What are the most common medical cases involving negligence?

The largest categories of medical negligence cases in England by volume are emergency medicine, orthopaedic surgery, and obstetrics. According to NHS Resolution, emergency medicine accounted for 13.1% of new claims in 2024-25, orthopaedic surgery for 11.5%, and obstetrics for 11.2%. Together these three specialties represent over a quarter of all new clinical negligence claims that year.

The distribution by value tells a different story. Obstetrics represents only 11.2% of new claims but accounts for over half of total claim value paid by NHS Resolution in 2024-25. This is because birth injury claims frequently involve lifelong care needs: the projected cost of care, adapted accommodation, specialist equipment, and lost future earnings can run into tens of millions of pounds for a single case.

Across all specialties, delayed or missed diagnosis is the most common underlying trigger. It dominates emergency medicine claims and GP negligence cases under the Clinical Negligence Scheme for General Practice. The NAO has noted that the cost of settling clinical negligence claims has more than tripled over two decades, partly reflecting the growing volume and complexity of diagnostic failure cases.

Why is delayed diagnosis the most litigated type?

Delayed diagnosis is the most litigated category of medical negligence because it is the most common clinical failure, appearing across primary care, emergency medicine, and secondary care specialties in significant volumes.

A delayed diagnosis claim arises when a clinician fails to identify a condition in time: by missing warning signs, not ordering appropriate tests, or not making a timely referral. The breach element is established by showing that a competent clinician, presented with the same symptoms and information, would have referred or investigated earlier. The harder question is causation: would earlier diagnosis actually have changed the outcome?

In cancer cases, this requires expert oncological evidence comparing the prognosis at the stage the cancer was actually diagnosed against the prognosis at the stage it should have been identified. In Cauda Equina Syndrome (CES) cases (NHS Resolution cases document these as a recurring type), the window for spinal cord decompression can be a matter of hours. A delay in MRI referral or surgery, even by a day, can be the difference between partial and permanent paralysis. These cases turn on whether a competent clinician in the relevant department would have escalated more quickly, and on what the outcome would have been had they done so.

Why are birth injury cases the highest-value claims?

Birth injury cases represent the largest single category of claim value in the NHS clinical negligence system, and the reason is straightforward: they frequently involve a child who will require intensive support for the rest of their life.

The most common failures giving rise to maternity claims are: inadequate monitoring of foetal heart rate during labour (CTG monitoring failures), delays in performing an emergency Caesarean section when signs of foetal distress are present, and mismanagement of complications such as shoulder dystocia. Montgomery v Lanarkshire Health Board [2015] UKSC 11 was itself a maternity case. Nadine Montgomery was diabetic, carrying a larger than usual baby, and at heightened risk of shoulder dystocia. Her obstetric team did not disclose that risk or offer elective Caesarean section. When dystocia occurred during labour, her son was born with severe disabilities. The Supreme Court held that failure to disclose a risk a reasonable patient would consider significant is negligence: the Bolam test does not apply to consent.

These cases are usually funded through a Conditional Fee Agreement (CFA). Legal aid remains available for one specific category: a child who has suffered a severe neurological injury at birth. A specialist solicitor will advise whether legal aid is the right funding route for a particular birth injury claim.

What types of surgical error give rise to a claim?

Surgical negligence covers a wide range of failures, and the most clear-cut cases are those where the error is objectively indefensible on the Bolam standard.

Wrong-site surgery (operating on the wrong limb, joint, or organ) is among the most straightforward surgical negligence cases on breach. A retained surgical instrument, an avoidable perforation of an adjacent organ during a procedure, and negligent post-operative care each give rise to distinct factual patterns. Where the error is apparent from the surgical notes and the connection to harm is direct, these cases tend to resolve without the lengthy causation disputes that characterise delayed diagnosis claims.

Other categories include anaesthesia errors (awareness under anaesthesia, intubation failures, overdose), medication errors (wrong drug, wrong dose, contraindicated prescriptions), and hospital-acquired infections where the infection is shown to have been negligently caused rather than being an unavoidable risk of the procedure. Ophthalmology and cosmetic surgery negligence follow the same legal framework, with the Bolam and Bolitho standards governing breach and the "but for" test governing causation.

Landmark medical negligence cases that shaped the law

Four cases define the legal framework applied to every clinical negligence claim in England and Wales today. Understanding what each decided explains why the same questions arise in case after case.

Bolam v Friern Hospital Management Committee [1957] 1 WLR 582. John Bolam suffered fractures during electro-convulsive therapy at Friern Hospital. The hospital had not used muscle relaxants or restraints, and had not warned him of the fracture risk. The court held the hospital was not negligent because its approach conformed to a responsible body of medical opinion at the time. The Bolam test has been applied to every clinical negligence breach question ever since.

Bolitho v City and Hackney Health Authority [1997] UKHL 46. Two-year-old Patrick Bolitho suffered a respiratory arrest. The on-call paediatric registrar failed to attend when called, which was a breach of duty. The defence argued that even if she had attended, she would not have intubated him, and that a decision not to intubate was clinically defensible. The House of Lords accepted this argument but added an important qualification: the responsible body of opinion relied on under Bolam must be capable of withstanding logical analysis. A court is not required to accept expert evidence that is internally inconsistent or fails to weigh risks and benefits properly. The claim failed on causation.

Montgomery v Lanarkshire Health Board [2015] UKSC 11. The Supreme Court held that consent and risk disclosure are not governed by the Bolam test. A doctor must disclose any risk that a reasonable patient in the claimant's individual position would consider significant when deciding whether to proceed with treatment. The standard is patient-centred, not clinician-centred. This replaced the previous approach, under which disclosure decisions were treated as a matter of clinical judgment.

Barnett v Chelsea and Kensington Hospital [1969] 1 QB 428. Three night watchmen attended the casualty department after drinking tea laced with arsenic. The duty doctor, himself unwell, did not examine them and told a nurse to advise them to go home. One man died of arsenic poisoning. The hospital was found to have breached its duty by failing to assess and treat him. However, the claim failed on causation: the arsenic dose was already lethal and he would have died even with prompt treatment. This case established the "but for" causation test and remains the clearest illustration of why breach alone is not sufficient.

Reading the patterns in real medical negligence cases

These categories recur because the underlying clinical failures recur. Missed cancer referrals, CTG monitoring failures, wrong-site procedures, and consent failures all appear in the records year after year because they represent points where clinical systems break down.

What that means in practice is that if your experience resembles one of these patterns, the legal tests and the expert evidence required are well understood. It does not mean your claim will succeed: every case turns on its specific facts, and causation in particular is always fact-specific. A claim that appears strong on breach can still fail if the expert evidence does not support the causation argument.

The first practical step is obtaining your medical records. You have a legal right to access them, and they are the evidential foundation of any claim. A specialist solicitor will request them on your behalf, but you can also request them directly from your GP or NHS trust at any point. Acting early means the records are more complete and the recollections of treating clinicians are fresher.

Starting a claim

AAA Solicitors handles all categories of medical negligence claims in England and Wales on a no win no fee basis. An initial assessment is free and commits you to nothing.

You can check your claim using the online form or call to speak with a specialist. The claims process guide covers every stage from first instruction to settlement. For an explanation of how a CFA funding arrangement works and what the 25% success fee cap means in practice, that guide is also on this site.